FFmpegWriter.cpp

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/**
 * @file
 * @brief Source file for FFmpegWriter class
 * @author Jonathan Thomas <jonathan@openshot.org>, Fabrice Bellard
 *
 * @section LICENSE
 *
 * Copyright (c) 2008-2013 OpenShot Studios, LLC, Fabrice Bellard
 * (http://www.openshotstudios.com). This file is part of
 * OpenShot Library (http://www.openshot.org), an open-source project
 * dedicated to delivering high quality video editing and animation solutions
 * to the world.
 *
 * This file is originally based on the Libavformat API example, and then modified
 * by the libopenshot project.
 *
 * OpenShot Library (libopenshot) is free software: you can redistribute it
 * and/or modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * OpenShot Library (libopenshot) is distributed in the hope that it will be
 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with OpenShot Library. If not, see <http://www.gnu.org/licenses/>.
 */

#include "../include/FFmpegWriter.h"

using namespace openshot;

FFmpegWriter::FFmpegWriter(string path) throw (InvalidFile, InvalidFormat, InvalidCodec, InvalidOptions, OutOfMemory):
                path(path), fmt(NULL), oc(NULL), audio_st(NULL), video_st(NULL), audio_pts(0), video_pts(0), samples(NULL),
                audio_outbuf(NULL), audio_outbuf_size(0), audio_input_frame_size(0), audio_input_position(0),
                initial_audio_input_frame_size(0), img_convert_ctx(NULL), cache_size(8), num_of_rescalers(32),
                rescaler_position(0), video_codec(NULL), audio_codec(NULL), is_writing(false), write_video_count(0), write_audio_count(0),
                original_sample_rate(0), original_channels(0), avr(NULL), avr_planar(NULL), is_open(false), prepare_streams(false),
                write_header(false), write_trailer(false), audio_encoder_buffer_size(0), audio_encoder_buffer(NULL)
{

        // Disable audio & video (so they can be independently enabled)
        info.has_audio = false;
        info.has_video = false;

        // Initialize FFMpeg, and register all formats and codecs
        av_register_all();

        // auto detect format
        auto_detect_format();
}

// Open the writer
void FFmpegWriter::Open() throw(InvalidFile, InvalidFormat, InvalidCodec, InvalidOptions, OutOfMemory, InvalidChannels, InvalidSampleRate)
{
        // Open the writer
        is_open = true;

        // Prepare streams (if needed)
        if (!prepare_streams)
                PrepareStreams();

        // Write header (if needed)
        if (!write_header)
                WriteHeader();
}

// auto detect format (from path)
void FFmpegWriter::auto_detect_format()
{
        // Auto detect the output format from the name. default is mpeg.
        fmt = av_guess_format(NULL, path.c_str(), NULL);
        if (!fmt)
                throw InvalidFormat("Could not deduce output format from file extension.", path);

        // Allocate the output media context
        oc = avformat_alloc_context();
        if (!oc)
                throw OutOfMemory("Could not allocate memory for AVFormatContext.", path);

        // Set the AVOutputFormat for the current AVFormatContext
        oc->oformat = fmt;

        // Update codec names
        if (fmt->video_codec != AV_CODEC_ID_NONE && info.has_video)
                // Update video codec name
                info.vcodec = avcodec_find_encoder(fmt->video_codec)->name;

        if (fmt->audio_codec != AV_CODEC_ID_NONE && info.has_audio)
                // Update audio codec name
                info.acodec = avcodec_find_encoder(fmt->audio_codec)->name;
}

// initialize streams
void FFmpegWriter::initialize_streams()
{
        AppendDebugMethod("FFmpegWriter::initialize_streams", "fmt->video_codec", fmt->video_codec, "fmt->audio_codec", fmt->audio_codec, "AV_CODEC_ID_NONE", AV_CODEC_ID_NONE, "", -1, "", -1, "", -1);

        // Add the audio and video streams using the default format codecs and initialize the codecs
        video_st = NULL;
        audio_st = NULL;
        if (fmt->video_codec != AV_CODEC_ID_NONE && info.has_video)
                // Add video stream
                video_st = add_video_stream();

        if (fmt->audio_codec != AV_CODEC_ID_NONE && info.has_audio)
                // Add audio stream
                audio_st = add_audio_stream();
}

// Set video export options
void FFmpegWriter::SetVideoOptions(bool has_video, string codec, Fraction fps, int width, int height, Fraction pixel_ratio, bool interlaced, bool top_field_first, int bit_rate)
        throw(InvalidFile, InvalidFormat, InvalidCodec, InvalidOptions, OutOfMemory, InvalidChannels)
{
        // Set the video options
        if (codec.length() > 0)
        {
                AVCodec *new_codec = avcodec_find_encoder_by_name(codec.c_str());
                if (new_codec == NULL)
                        throw InvalidCodec("A valid audio codec could not be found for this file.", path);
                else {
                        // Set video codec
                        info.vcodec = new_codec->name;

                        // Update video codec in fmt
                        fmt->video_codec = new_codec->id;
                }
        }
        if (fps.num > 0)
        {
                // Set frames per second (if provided)
                info.fps.num = fps.num;
                info.fps.den = fps.den;

                // Set the timebase (inverse of fps)
                info.video_timebase.num = info.fps.den;
                info.video_timebase.den = info.fps.num;
        }
        if (width >= 1)
                info.width = width;
        if (height >= 1)
                info.height = height;
        if (pixel_ratio.num > 0)
        {
                info.pixel_ratio.num = pixel_ratio.num;
                info.pixel_ratio.den = pixel_ratio.den;
        }
        if (bit_rate >= 1000)
                info.video_bit_rate = bit_rate;

        info.interlaced_frame = interlaced;
        info.top_field_first = top_field_first;

        // Calculate the DAR (display aspect ratio)
        Fraction size(info.width * info.pixel_ratio.num, info.height * info.pixel_ratio.den);

        // Reduce size fraction
        size.Reduce();

        // Set the ratio based on the reduced fraction
        info.display_ratio.num = size.num;
        info.display_ratio.den = size.den;

        AppendDebugMethod("FFmpegWriter::SetVideoOptions (" + codec + ")", "width", width, "height", height, "size.num", size.num, "size.den", size.den, "fps.num", fps.num, "fps.den", fps.den);

        // Enable / Disable video
        info.has_video = has_video;
}

// Set audio export options
void FFmpegWriter::SetAudioOptions(bool has_audio, string codec, int sample_rate, int channels, ChannelLayout channel_layout, int bit_rate)
        throw(InvalidFile, InvalidFormat, InvalidCodec, InvalidOptions, OutOfMemory, InvalidChannels)
{
        // Set audio options
        if (codec.length() > 0)
        {
                AVCodec *new_codec = avcodec_find_encoder_by_name(codec.c_str());
                if (new_codec == NULL)
                        throw InvalidCodec("A valid audio codec could not be found for this file.", path);
                else
                {
                        // Set audio codec
                        info.acodec = new_codec->name;

                        // Update audio codec in fmt
                        fmt->audio_codec = new_codec->id;
                }
        }
        if (sample_rate > 7999)
                info.sample_rate = sample_rate;
        if (channels > 0)
                info.channels = channels;
        if (bit_rate > 999)
                info.audio_bit_rate = bit_rate;
        info.channel_layout = channel_layout;

        // init resample options (if zero)
        if (original_sample_rate == 0)
                original_sample_rate = info.sample_rate;
        if (original_channels == 0)
                original_channels = info.channels;

        AppendDebugMethod("FFmpegWriter::SetAudioOptions (" + codec + ")", "sample_rate", sample_rate, "channels", channels, "bit_rate", bit_rate, "", -1, "", -1, "", -1);

        // Enable / Disable audio
        info.has_audio = has_audio;
}

// Set custom options (some codecs accept additional params)
void FFmpegWriter::SetOption(StreamType stream, string name, string value) throw(NoStreamsFound, InvalidOptions)
{
        // Declare codec context
        AVCodecContext *c = NULL;
        stringstream convert(value);

        if (info.has_video && stream == VIDEO_STREAM && video_st)
                c = video_st->codec;
        else if (info.has_audio && stream == AUDIO_STREAM && audio_st)
                c = audio_st->codec;
        else
                throw NoStreamsFound("The stream was not found. Be sure to call PrepareStreams() first.", path);

        // Init AVOption
        const AVOption *option = NULL;

        // Was a codec / stream found?
        if (c)
                // Find AVOption (if it exists)
                #if LIBAVFORMAT_VERSION_MAJOR <= 53
                        option = av_find_opt(c->priv_data, name.c_str(), NULL, NULL, NULL);
                #else
                        option = av_opt_find(c->priv_data, name.c_str(), NULL, 0, 0);
                #endif

        // Was option found?
        if (option || (name == "g" || name == "qmin" || name == "qmax" || name == "max_b_frames" || name == "mb_decision" ||
                               name == "level" || name == "profile" || name == "slices" || name == "rc_min_rate"  || name == "rc_max_rate"))
        {
                // Check for specific named options
                if (name == "g")
                        // Set gop_size
                        convert >> c->gop_size;

                else if (name == "qmin")
                        // Minimum quantizer
                        convert >> c->qmin;

                else if (name == "qmax")
                        // Maximum quantizer
                        convert >> c->qmax;

                else if (name == "max_b_frames")
                        // Maximum number of B-frames between non-B-frames
                        convert >> c->max_b_frames;

                else if (name == "mb_decision")
                        // Macroblock decision mode
                        convert >> c->mb_decision;

                else if (name == "level")
                        // Set codec level
                        convert >> c->level;

                else if (name == "profile")
                        // Set codec profile
                        convert >> c->profile;

                else if (name == "slices")
                        // Indicates number of picture subdivisions
                        convert >> c->slices;

                else if (name == "rc_min_rate")
                        // Minimum bitrate
                        convert >> c->rc_min_rate;

                else if (name == "rc_max_rate")
                        // Maximum bitrate
                        convert >> c->rc_max_rate;

                else if (name == "rc_buffer_size")
                        // Buffer size
                        convert >> c->rc_buffer_size;

                else
                        // Set AVOption
                        #if LIBAVFORMAT_VERSION_MAJOR <= 53
                                av_set_string3 (c->priv_data, name.c_str(), value.c_str(), 0, NULL);
                        #else
                                av_opt_set (c->priv_data, name.c_str(), value.c_str(), 0);
                        #endif

                AppendDebugMethod("FFmpegWriter::SetOption (" + (string)name + ")", "stream == VIDEO_STREAM", stream == VIDEO_STREAM, "", -1, "", -1, "", -1, "", -1, "", -1);

        }
        else
                throw InvalidOptions("The option is not valid for this codec.", path);

}

// Prepare & initialize streams and open codecs
void FFmpegWriter::PrepareStreams()
{
        if (!info.has_audio && !info.has_video)
                throw InvalidOptions("No video or audio options have been set.  You must set has_video or has_audio (or both).", path);

        AppendDebugMethod("FFmpegWriter::PrepareStreams [" + path + "]", "info.has_audio", info.has_audio, "info.has_video", info.has_video, "", -1, "", -1, "", -1, "", -1);

        // Initialize the streams (i.e. add the streams)
        initialize_streams();

        // Now that all the parameters are set, we can open the audio and video codecs and allocate the necessary encode buffers
        if (info.has_video && video_st)
                open_video(oc, video_st);
        if (info.has_audio && audio_st)
                open_audio(oc, audio_st);

        // Mark as 'prepared'
        prepare_streams = true;
}

// Write the file header (after the options are set)
void FFmpegWriter::WriteHeader()
{
        if (!info.has_audio && !info.has_video)
                throw InvalidOptions("No video or audio options have been set.  You must set has_video or has_audio (or both).", path);

        // Open the output file, if needed
        if (!(fmt->flags & AVFMT_NOFILE)) {
                if (avio_open(&oc->pb, path.c_str(), AVIO_FLAG_WRITE) < 0)
                        throw InvalidFile("Could not open or write file.", path);
        }

        // Write the stream header, if any
        // TODO: add avoptions / parameters instead of NULL
        avformat_write_header(oc, NULL);

        // Mark as 'written'
        write_header = true;

        AppendDebugMethod("FFmpegWriter::WriteHeader", "", -1, "", -1, "", -1, "", -1, "", -1, "", -1);
}

// Add a frame to the queue waiting to be encoded.
void FFmpegWriter::WriteFrame(tr1::shared_ptr<Frame> frame) throw(ErrorEncodingVideo, WriterClosed)
{
        // Check for open reader (or throw exception)
        if (!is_open)
                throw WriterClosed("The FFmpegWriter is closed.  Call Open() before calling this method.", path);

        // Add frame pointer to "queue", waiting to be processed the next
        // time the WriteFrames() method is called.
        if (info.has_video && video_st)
                spooled_video_frames.push_back(frame);

        if (info.has_audio && audio_st)
                spooled_audio_frames.push_back(frame);

        AppendDebugMethod("FFmpegWriter::WriteFrame", "frame->number", frame->number, "spooled_video_frames.size()", spooled_video_frames.size(), "spooled_audio_frames.size()", spooled_audio_frames.size(), "cache_size", cache_size, "is_writing", is_writing, "", -1);

        // Write the frames once it reaches the correct cache size
        if (spooled_video_frames.size() == cache_size || spooled_audio_frames.size() == cache_size)
        {
                // Is writer currently writing?
                if (!is_writing)
                        // Write frames to video file
                        write_queued_frames();

                else
                {
                        // YES, WRITING... so wait until it finishes, before writing again
                        while (is_writing)
                                usleep(250000); // sleep for 250 milliseconds

                        // Write frames to video file
                        write_queued_frames();
                }
        }

        // Keep track of the last frame added
        last_frame = frame;
}

// Write all frames in the queue to the video file.
void FFmpegWriter::write_queued_frames() throw (ErrorEncodingVideo)
{
        AppendDebugMethod("FFmpegWriter::write_queued_frames", "spooled_video_frames.size()", spooled_video_frames.size(), "spooled_audio_frames.size()", spooled_audio_frames.size(), "", -1, "", -1, "", -1, "", -1);

        // Flip writing flag
        is_writing = true;

        // Transfer spool to queue
        queued_video_frames = spooled_video_frames;
        queued_audio_frames = spooled_audio_frames;

        // Empty spool
        spooled_video_frames.clear();
        spooled_audio_frames.clear();

        // Set the number of threads in OpenMP
        omp_set_num_threads(OPEN_MP_NUM_PROCESSORS);
        // Allow nested OpenMP sections
        omp_set_nested(true);

        // Create blank exception
        bool has_error_encoding_video = false;

        #pragma omp parallel
        {
                #pragma omp single
                {
                        // Process all audio frames (in a separate thread)
                        if (info.has_audio && audio_st && !queued_audio_frames.empty())
                                write_audio_packets(false);

                        // Loop through each queued image frame
                        while (!queued_video_frames.empty())
                        {
                                // Get front frame (from the queue)
                                tr1::shared_ptr<Frame> frame = queued_video_frames.front();

                                // Add to processed queue
                                processed_frames.push_back(frame);

                                // Encode and add the frame to the output file
                                if (info.has_video && video_st)
                                        process_video_packet(frame);

                                // Remove front item
                                queued_video_frames.pop_front();

                        } // end while
                } // end omp single

                #pragma omp single
                {
                        // Loop back through the frames (in order), and write them to the video file
                        while (!processed_frames.empty())
                        {
                                // Get front frame (from the queue)
                                tr1::shared_ptr<Frame> frame = processed_frames.front();

                                if (info.has_video && video_st)
                                {
                                        // Add to deallocate queue (so we can remove the AVFrames when we are done)
                                        deallocate_frames.push_back(frame);

                                        // Does this frame's AVFrame still exist
                                        if (av_frames.count(frame))
                                        {
                                                // Get AVFrame
                                                AVFrame *frame_final = av_frames[frame];

                                                // Write frame to video file
                                                bool success = write_video_packet(frame, frame_final);
                                                if (!success)
                                                        has_error_encoding_video = true;
                                        }
                                }

                                // Remove front item
                                processed_frames.pop_front();
                        }

                        // Loop through, and deallocate AVFrames
                        while (!deallocate_frames.empty())
                        {
                                // Get front frame (from the queue)
                                tr1::shared_ptr<Frame> frame = deallocate_frames.front();

                                // Does this frame's AVFrame still exist
                                if (av_frames.count(frame))
                                {
                                        // Get AVFrame
                                        AVFrame *av_frame = av_frames[frame];

                                        // Deallocate AVPicture and AVFrame
                                        free(av_frame->data[0]); // TODO: Determine why av_free crashes on Windows
                                        AV_FREE_FRAME(&av_frame);
                                        av_frames.erase(frame);
                                }

                                // Remove front item
                                deallocate_frames.pop_front();
                        }

                        // Done writing
                        is_writing = false;

                } // end omp single
        } // end omp parallel

        // Raise exception from main thread
        if (has_error_encoding_video)
                throw ErrorEncodingVideo("Error while writing raw video frame", -1);
}

// Write a block of frames from a reader
void FFmpegWriter::WriteFrame(ReaderBase* reader, long int start, long int length) throw(ErrorEncodingVideo, WriterClosed)
{
        AppendDebugMethod("FFmpegWriter::WriteFrame (from Reader)", "start", start, "length", length, "", -1, "", -1, "", -1, "", -1);

        // Loop through each frame (and encoded it)
        for (long int number = start; number <= length; number++)
        {
                // Get the frame
                tr1::shared_ptr<Frame> f = reader->GetFrame(number);

                // Encode frame
                WriteFrame(f);
        }
}

// Write the file trailer (after all frames are written)
void FFmpegWriter::WriteTrailer()
{
        // Write any remaining queued frames to video file
        write_queued_frames();

        // Process final audio frame (if any)
        if (info.has_audio && audio_st)
                write_audio_packets(true);

        // Flush encoders (who sometimes hold on to frames)
        flush_encoders();

        /* write the trailer, if any. The trailer must be written
         * before you close the CodecContexts open when you wrote the
         * header; otherwise write_trailer may try to use memory that
         * was freed on av_codec_close() */
        av_write_trailer(oc);

        // Mark as 'written'
        write_trailer = true;

        AppendDebugMethod("FFmpegWriter::WriteTrailer", "", -1, "", -1, "", -1, "", -1, "", -1, "", -1);
}

// Flush encoders
void FFmpegWriter::flush_encoders()
{
    if (info.has_audio && audio_codec && audio_st->codec->codec_type == AVMEDIA_TYPE_AUDIO && audio_codec->frame_size <= 1)
        return;
    if (info.has_video && video_st->codec->codec_type == AVMEDIA_TYPE_VIDEO && (oc->oformat->flags & AVFMT_RAWPICTURE) && video_codec->codec->id == AV_CODEC_ID_RAWVIDEO)
        return;

    int error_code = 0;
    int stop_encoding = 1;

    // FLUSH VIDEO ENCODER
    if (info.has_video)
                for (;;) {

                        // Increment PTS (in frames and scaled to the codec's timebase)
                        write_video_count += av_rescale_q(1, (AVRational){info.fps.den, info.fps.num}, video_codec->time_base);

                        AVPacket pkt;
                        av_init_packet(&pkt);
                        pkt.data = NULL;
                        pkt.size = 0;

                        // Pointer for video buffer (if using old FFmpeg version)
                        uint8_t *video_outbuf = NULL;

                        /* encode the image */
                        int got_packet = 0;
                        int error_code = 0;

                        #if LIBAVFORMAT_VERSION_MAJOR >= 54
                                // Newer versions of FFMpeg
                        error_code = avcodec_encode_video2(video_codec, &pkt, NULL, &got_packet);

                        #else
                                // Older versions of FFmpeg (much sloppier)

                                // Encode Picture and Write Frame
                                int video_outbuf_size = 0;
                                //video_outbuf = new uint8_t[200000];

                                /* encode the image */
                                int out_size = avcodec_encode_video(video_codec, NULL, video_outbuf_size, NULL);

                                /* if zero size, it means the image was buffered */
                                if (out_size > 0) {
                                        if(video_codec->coded_frame->key_frame)
                                                pkt.flags |= AV_PKT_FLAG_KEY;
                                        pkt.data= video_outbuf;
                                        pkt.size= out_size;

                                        // got data back (so encode this frame)
                                        got_packet = 1;
                                }
                        #endif

                        if (error_code < 0) {
                                AppendDebugMethod("FFmpegWriter::flush_encoders ERROR [" + (string)av_err2str(error_code) + "]", "error_code", error_code, "", -1, "", -1, "", -1, "", -1, "", -1);
                        }
                        if (!got_packet) {
                                stop_encoding = 1;
                                break;
                        }

                        // Override PTS (in frames and scaled to the codec's timebase)
                        //pkt.pts = write_video_count;

                        // set the timestamp
                        if (pkt.pts != AV_NOPTS_VALUE)
                                pkt.pts = av_rescale_q(pkt.pts, video_codec->time_base, video_st->time_base);
                        if (pkt.dts != AV_NOPTS_VALUE)
                                pkt.dts = av_rescale_q(pkt.dts, video_codec->time_base, video_st->time_base);
                        if (pkt.duration > 0)
                                pkt.duration = av_rescale_q(pkt.duration, video_codec->time_base, video_st->time_base);
                        pkt.stream_index = video_st->index;

                        // Write packet
                        error_code = av_interleaved_write_frame(oc, &pkt);
                        if (error_code < 0) {
                                AppendDebugMethod("FFmpegWriter::flush_encoders ERROR [" + (string)av_err2str(error_code) + "]", "error_code", error_code, "", -1, "", -1, "", -1, "", -1, "", -1);
                        }

                        // Deallocate memory (if needed)
                        if (video_outbuf)
                                delete[] video_outbuf;
                }

    // FLUSH AUDIO ENCODER
    if (info.has_audio)
                for (;;) {

                        // Increment PTS (in samples and scaled to the codec's timebase)
#if LIBAVFORMAT_VERSION_MAJOR >= 54
                        // for some reason, it requires me to multiply channels X 2
                        write_audio_count += av_rescale_q(audio_input_position / (audio_codec->channels * av_get_bytes_per_sample(AV_SAMPLE_FMT_S16)), (AVRational){1, info.sample_rate}, audio_codec->time_base);
#else
                        write_audio_count += av_rescale_q(audio_input_position / audio_codec->channels, (AVRational){1, info.sample_rate}, audio_codec->time_base);
#endif

                        AVPacket pkt;
                        av_init_packet(&pkt);
                        pkt.data = NULL;
                        pkt.size = 0;
                        pkt.pts = pkt.dts = write_audio_count;

                        /* encode the image */
                        int got_packet = 0;
                        error_code = avcodec_encode_audio2(audio_codec, &pkt, NULL, &got_packet);
                        if (error_code < 0) {
                                AppendDebugMethod("FFmpegWriter::flush_encoders ERROR [" + (string)av_err2str(error_code) + "]", "error_code", error_code, "", -1, "", -1, "", -1, "", -1, "", -1);
                        }
                        if (!got_packet) {
                                stop_encoding = 1;
                                break;
                        }

                        // Since the PTS can change during encoding, set the value again.  This seems like a huge hack,
                        // but it fixes lots of PTS related issues when I do this.
                        pkt.pts = pkt.dts = write_audio_count;

                        // Scale the PTS to the audio stream timebase (which is sometimes different than the codec's timebase)
                        if (pkt.pts != AV_NOPTS_VALUE)
                                pkt.pts = av_rescale_q(pkt.pts, audio_codec->time_base, audio_st->time_base);
                        if (pkt.dts != AV_NOPTS_VALUE)
                                pkt.dts = av_rescale_q(pkt.dts, audio_codec->time_base, audio_st->time_base);
                        if (pkt.duration > 0)
                                pkt.duration = av_rescale_q(pkt.duration, audio_codec->time_base, audio_st->time_base);

                        // set stream
                        pkt.stream_index = audio_st->index;
                        pkt.flags |= AV_PKT_FLAG_KEY;

                        // Write packet
                        error_code = av_interleaved_write_frame(oc, &pkt);
                        if (error_code < 0) {
                                AppendDebugMethod("FFmpegWriter::flush_encoders ERROR [" + (string)av_err2str(error_code) + "]", "error_code", error_code, "", -1, "", -1, "", -1, "", -1, "", -1);
                        }

                        // deallocate memory for packet
                        av_free_packet(&pkt);
                }


}

// Close the video codec
void FFmpegWriter::close_video(AVFormatContext *oc, AVStream *st)
{
        avcodec_close(st->codec);
        video_codec = NULL;
}

// Close the audio codec
void FFmpegWriter::close_audio(AVFormatContext *oc, AVStream *st)
{
        avcodec_close(st->codec);
        audio_codec = NULL;

        // Clear buffers
        delete[] samples;
        delete[] audio_outbuf;
        delete[] audio_encoder_buffer;
        samples = NULL;
        audio_outbuf = NULL;
        audio_encoder_buffer = NULL;

        // Deallocate resample buffer
        if (avr) {
                avresample_close(avr);
                avresample_free(&avr);
                avr = NULL;
        }

        if (avr_planar) {
                avresample_close(avr_planar);
                avresample_free(&avr_planar);
                avr_planar = NULL;
        }
}

// Close the writer
void FFmpegWriter::Close()
{
        // Write trailer (if needed)
        if (!write_trailer)
                WriteTrailer();

        // Close each codec
        if (video_st)
                close_video(oc, video_st);
        if (audio_st)
                close_audio(oc, audio_st);

        // Deallocate image scalers
        if (image_rescalers.size() > 0)
                RemoveScalers();

        // Free the streams
        for (int i = 0; i < oc->nb_streams; i++) {
                av_freep(&oc->streams[i]->codec);
                av_freep(&oc->streams[i]);
        }

        if (!(fmt->flags & AVFMT_NOFILE)) {
                /* close the output file */
                avio_close(oc->pb);
        }

        // Reset frame counters
        write_video_count = 0;
        write_audio_count = 0;

        // Free the context
        av_freep(&oc);

        // Close writer
        is_open = false;
        prepare_streams = false;
        write_header = false;
        write_trailer = false;

        AppendDebugMethod("FFmpegWriter::Close", "", -1, "", -1, "", -1, "", -1, "", -1, "", -1);
}

// Add an AVFrame to the cache
void FFmpegWriter::add_avframe(tr1::shared_ptr<Frame> frame, AVFrame* av_frame)
{
        // Add AVFrame to map (if it does not already exist)
        if (!av_frames.count(frame))
        {
                // Add av_frame
                av_frames[frame] = av_frame;
        }
        else
        {
                // Do not add, and deallocate this AVFrame
                AV_FREE_FRAME(&av_frame);
        }
}

// Add an audio output stream
AVStream* FFmpegWriter::add_audio_stream()
{
        AVCodecContext *c;
        AVStream *st;

        // Find the audio codec
        AVCodec *codec = avcodec_find_encoder_by_name(info.acodec.c_str());
        if (codec == NULL)
                throw InvalidCodec("A valid audio codec could not be found for this file.", path);

        // Create a new audio stream
        st = avformat_new_stream(oc, codec);
        if (!st)
                throw OutOfMemory("Could not allocate memory for the audio stream.", path);

        // Set default values
    avcodec_get_context_defaults3(st->codec, codec);

        c = st->codec;
        c->codec_id = codec->id;
#if LIBAVFORMAT_VERSION_MAJOR >= 53
        c->codec_type = AVMEDIA_TYPE_AUDIO;
#else
        c->codec_type = CODEC_TYPE_AUDIO;
#endif

        // Set the sample parameters
        c->bit_rate = info.audio_bit_rate;
        c->channels = info.channels;

        // Set valid sample rate (or throw error)
        if (codec->supported_samplerates) {
                int i;
            for (i = 0; codec->supported_samplerates[i] != 0; i++)
                if (info.sample_rate == codec->supported_samplerates[i])
                {
                        // Set the valid sample rate
                        c->sample_rate = info.sample_rate;
                    break;
                }
            if (codec->supported_samplerates[i] == 0)
                throw InvalidSampleRate("An invalid sample rate was detected for this codec.", path);
        } else
                // Set sample rate
                c->sample_rate = info.sample_rate;


        // Set a valid number of channels (or throw error)
        int channel_layout = info.channel_layout;
        if (codec->channel_layouts) {
                int i;
                for (i = 0; codec->channel_layouts[i] != 0; i++)
                        if (channel_layout == codec->channel_layouts[i])
                        {
                                // Set valid channel layout
                                c->channel_layout = channel_layout;
                                break;
                        }
                if (codec->channel_layouts[i] == 0)
                        throw InvalidChannels("An invalid channel layout was detected (i.e. MONO / STEREO).", path);
        } else
                // Set valid channel layout
                c->channel_layout = channel_layout;

        // Choose a valid sample_fmt
        if (codec->sample_fmts) {
                for (int i = 0; codec->sample_fmts[i] != AV_SAMPLE_FMT_NONE; i++)
                {
                        // Set sample format to 1st valid format (and then exit loop)
                        c->sample_fmt = codec->sample_fmts[i];
                        break;
                }
        }
        if (c->sample_fmt == AV_SAMPLE_FMT_NONE) {
                // Default if no sample formats found
                c->sample_fmt = AV_SAMPLE_FMT_S16;
        }

        // some formats want stream headers to be separate
        if (oc->oformat->flags & AVFMT_GLOBALHEADER)
                c->flags |= CODEC_FLAG_GLOBAL_HEADER;

        AppendDebugMethod("FFmpegWriter::add_audio_stream", "c->codec_id", c->codec_id, "c->bit_rate", c->bit_rate, "c->channels", c->channels, "c->sample_fmt", c->sample_fmt, "c->channel_layout", c->channel_layout, "c->sample_rate", c->sample_rate);

        return st;
}

// Add a video output stream
AVStream* FFmpegWriter::add_video_stream()
{
        AVCodecContext *c;
        AVStream *st;

        // Find the audio codec
        AVCodec *codec = avcodec_find_encoder_by_name(info.vcodec.c_str());
        if (codec == NULL)
                throw InvalidCodec("A valid video codec could not be found for this file.", path);

        // Create a new stream
        st = avformat_new_stream(oc, codec);
        if (!st)
                throw OutOfMemory("Could not allocate memory for the video stream.", path);

        // Set default values
    avcodec_get_context_defaults3(st->codec, codec);

        c = st->codec;
        c->codec_id = codec->id;
#if LIBAVFORMAT_VERSION_MAJOR >= 53
        c->codec_type = AVMEDIA_TYPE_VIDEO;
#else
        c->codec_type = CODEC_TYPE_VIDEO;
#endif

        /* Init video encoder options */
        c->bit_rate = info.video_bit_rate;
        c->rc_min_rate = info.video_bit_rate - (info.video_bit_rate / 6);
        c->rc_max_rate = info.video_bit_rate;
        c->rc_buffer_size = FFMAX(c->rc_max_rate, 15000000) * 112L / 15000000 * 16384;
        c->qmin = 2;
        c->qmax = 30;

        /* resolution must be a multiple of two */
        // TODO: require /2 height and width
        c->width = info.width;
        c->height = info.height;

        /* time base: this is the fundamental unit of time (in seconds) in terms
         of which frame timestamps are represented. for fixed-fps content,
         timebase should be 1/framerate and timestamp increments should be
         identically 1. */
        c->time_base.num = info.video_timebase.num;
        c->time_base.den = info.video_timebase.den;
        c->gop_size = 12; /* TODO: add this to "info"... emit one intra frame every twelve frames at most */
        c->max_b_frames = 10;
        if (c->codec_id == AV_CODEC_ID_MPEG2VIDEO)
                /* just for testing, we also add B frames */
                c->max_b_frames = 2;
        if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO)
                /* Needed to avoid using macroblocks in which some coeffs overflow.
                 This does not happen with normal video, it just happens here as
                 the motion of the chroma plane does not match the luma plane. */
                c->mb_decision = 2;
        // some formats want stream headers to be separate
        if (oc->oformat->flags & AVFMT_GLOBALHEADER)
                c->flags |= CODEC_FLAG_GLOBAL_HEADER;

        // Find all supported pixel formats for this codec
    const PixelFormat* supported_pixel_formats = codec->pix_fmts;
    while (supported_pixel_formats != NULL && *supported_pixel_formats != PIX_FMT_NONE) {
        // Assign the 1st valid pixel format (if one is missing)
        if (c->pix_fmt == PIX_FMT_NONE)
                c->pix_fmt = *supported_pixel_formats;
        ++supported_pixel_formats;
    }

    // Codec doesn't have any pix formats?
    if (c->pix_fmt == PIX_FMT_NONE) {
        if(fmt->video_codec == AV_CODEC_ID_RAWVIDEO) {
            // Raw video should use RGB24
                c->pix_fmt = PIX_FMT_RGB24;

        if (strcmp(fmt->name, "gif") != 0)
                        // If not GIF format, skip the encoding process
                        // Set raw picture flag (so we don't encode this video)
                        oc->oformat->flags |= AVFMT_RAWPICTURE;
        } else {
                // Set the default codec
                c->pix_fmt = PIX_FMT_YUV420P;
        }
    }

        AppendDebugMethod("FFmpegWriter::add_video_stream (" + (string)fmt->name + " : " + (string)av_get_pix_fmt_name(c->pix_fmt) + ")", "c->codec_id", c->codec_id, "c->bit_rate", c->bit_rate, "c->pix_fmt", c->pix_fmt, "oc->oformat->flags", oc->oformat->flags, "AVFMT_RAWPICTURE", AVFMT_RAWPICTURE, "", -1);

        return st;
}

// open audio codec
void FFmpegWriter::open_audio(AVFormatContext *oc, AVStream *st)
{
        AVCodec *codec;
        audio_codec = st->codec;

        // Set number of threads equal to number of processors + 1
        audio_codec->thread_count = OPEN_MP_NUM_PROCESSORS;

        // Find the audio encoder
        codec = avcodec_find_encoder(audio_codec->codec_id);
        if (!codec)
                throw InvalidCodec("Could not find codec", path);

        // Open the codec
        if (avcodec_open2(audio_codec, codec, NULL) < 0)
                throw InvalidCodec("Could not open codec", path);

        // Calculate the size of the input frame (i..e how many samples per packet), and the output buffer
        // TODO: Ugly hack for PCM codecs (will be removed ASAP with new PCM support to compute the input frame size in samples
        if (audio_codec->frame_size <= 1) {
                // No frame size found... so calculate
                audio_input_frame_size = 50000 / info.channels;

                switch (st->codec->codec_id) {
                case AV_CODEC_ID_PCM_S16LE:
                case AV_CODEC_ID_PCM_S16BE:
                case AV_CODEC_ID_PCM_U16LE:
                case AV_CODEC_ID_PCM_U16BE:
                        audio_input_frame_size >>= 1;
                        break;
                default:
                        break;
                }
        } else {
                // Set frame size based on the codec
                audio_input_frame_size = audio_codec->frame_size;
        }

        // Set the initial frame size (since it might change during resampling)
        initial_audio_input_frame_size = audio_input_frame_size;

        // Allocate array for samples
        samples = new int16_t[AVCODEC_MAX_AUDIO_FRAME_SIZE];

        // Set audio output buffer (used to store the encoded audio)
        audio_outbuf_size = AVCODEC_MAX_AUDIO_FRAME_SIZE;
        audio_outbuf = new uint8_t[audio_outbuf_size];

        // Set audio packet encoding buffer
        audio_encoder_buffer_size = AUDIO_PACKET_ENCODING_SIZE;
        audio_encoder_buffer = new uint8_t[audio_encoder_buffer_size];

        AppendDebugMethod("FFmpegWriter::open_audio", "audio_codec->thread_count", audio_codec->thread_count, "audio_input_frame_size", audio_input_frame_size, "buffer_size", AVCODEC_MAX_AUDIO_FRAME_SIZE + FF_INPUT_BUFFER_PADDING_SIZE, "", -1, "", -1, "", -1);

}

// open video codec
void FFmpegWriter::open_video(AVFormatContext *oc, AVStream *st)
{
        AVCodec *codec;
        video_codec = st->codec;

        // Set number of threads equal to number of processors + 1
        video_codec->thread_count = OPEN_MP_NUM_PROCESSORS;

        /* find the video encoder */
        codec = avcodec_find_encoder(video_codec->codec_id);
        if (!codec)
                throw InvalidCodec("Could not find codec", path);

        /* open the codec */
        if (avcodec_open2(video_codec, codec, NULL) < 0)
                throw InvalidCodec("Could not open codec", path);

        AppendDebugMethod("FFmpegWriter::open_video", "video_codec->thread_count", video_codec->thread_count, "", -1, "", -1, "", -1, "", -1, "", -1);

}

// write all queued frames' audio to the video file
void FFmpegWriter::write_audio_packets(bool final)
{
        #pragma omp task firstprivate(final)
        {
                // Init audio buffers / variables
                int total_frame_samples = 0;
                int frame_position = 0;
                int channels_in_frame = 0;
                int sample_rate_in_frame = 0;
                int samples_in_frame = 0;
                ChannelLayout channel_layout_in_frame = LAYOUT_MONO; // default channel layout

                // Create a new array (to hold all S16 audio samples, for the current queued frames
                int16_t* all_queued_samples = new int16_t[(queued_audio_frames.size() * AVCODEC_MAX_AUDIO_FRAME_SIZE)];
                int16_t* all_resampled_samples = NULL;
                int16_t* final_samples_planar = NULL;
                int16_t* final_samples = NULL;

                // Loop through each queued audio frame
                while (!queued_audio_frames.empty())
                {
                        // Get front frame (from the queue)
                        tr1::shared_ptr<Frame> frame = queued_audio_frames.front();

                        // Get the audio details from this frame
                        sample_rate_in_frame = frame->SampleRate();
                        samples_in_frame = frame->GetAudioSamplesCount();
                        channels_in_frame = frame->GetAudioChannelsCount();
                        channel_layout_in_frame = frame->ChannelsLayout();


                        // Get audio sample array
                        float* frame_samples_float = NULL;
                        // Get samples interleaved together (c1 c2 c1 c2 c1 c2)
                        frame_samples_float = frame->GetInterleavedAudioSamples(sample_rate_in_frame, NULL, &samples_in_frame);


                        // Calculate total samples
                        total_frame_samples = samples_in_frame * channels_in_frame;

                        // Translate audio sample values back to 16 bit integers
                        for (int s = 0; s < total_frame_samples; s++, frame_position++)
                                // Translate sample value and copy into buffer
                                all_queued_samples[frame_position] = int(frame_samples_float[s] * (1 << 15));


                        // Deallocate float array
                        delete[] frame_samples_float;

                        // Remove front item
                        queued_audio_frames.pop_front();

                } // end while


                // Update total samples (since we've combined all queued frames)
                total_frame_samples = frame_position;
                int remaining_frame_samples = total_frame_samples;
                int samples_position = 0;


                AppendDebugMethod("FFmpegWriter::write_audio_packets", "final", final, "total_frame_samples", total_frame_samples, "channel_layout_in_frame", channel_layout_in_frame, "channels_in_frame", channels_in_frame, "samples_in_frame", samples_in_frame, "LAYOUT_MONO", LAYOUT_MONO);

                // Keep track of the original sample format
                AVSampleFormat output_sample_fmt = audio_codec->sample_fmt;

                AVFrame *audio_frame = NULL;
                if (!final) {
                        // Create input frame (and allocate arrays)
                        audio_frame = AV_ALLOCATE_FRAME();
                        AV_RESET_FRAME(audio_frame);
                        audio_frame->nb_samples = total_frame_samples / channels_in_frame;

                        // Fill input frame with sample data
                        avcodec_fill_audio_frame(audio_frame, channels_in_frame, AV_SAMPLE_FMT_S16, (uint8_t *) all_queued_samples,
                                        audio_encoder_buffer_size, 0);

                        // Do not convert audio to planar format (yet). We need to keep everything interleaved at this point.
                        switch (audio_codec->sample_fmt)
                        {
                                case AV_SAMPLE_FMT_FLTP:
                                {
                                        output_sample_fmt = AV_SAMPLE_FMT_FLT;
                                        break;
                                }
                                case AV_SAMPLE_FMT_S32P:
                                {
                                        output_sample_fmt = AV_SAMPLE_FMT_S32;
                                        break;
                                }
                                case AV_SAMPLE_FMT_S16P:
                                {
                                        output_sample_fmt = AV_SAMPLE_FMT_S16;
                                        break;
                                }
                                case AV_SAMPLE_FMT_U8P:
                                {
                                        output_sample_fmt = AV_SAMPLE_FMT_U8;
                                        break;
                                }
                        }

                        // Update total samples & input frame size (due to bigger or smaller data types)
                        total_frame_samples *= (float(info.sample_rate) / sample_rate_in_frame); // adjust for different byte sizes
                        total_frame_samples *= (float(info.channels) / channels_in_frame); // adjust for different # of channels

                        // Set remaining samples
                        remaining_frame_samples = total_frame_samples;

                        // Create output frame (and allocate arrays)
                        AVFrame *audio_converted = AV_ALLOCATE_FRAME();
                        AV_RESET_FRAME(audio_converted);
                        audio_converted->nb_samples = total_frame_samples / channels_in_frame;
                        av_samples_alloc(audio_converted->data, audio_converted->linesize, info.channels, audio_converted->nb_samples, output_sample_fmt, 0);

                        AppendDebugMethod("FFmpegWriter::write_audio_packets (1st resampling)", "in_sample_fmt", AV_SAMPLE_FMT_S16, "out_sample_fmt", output_sample_fmt, "in_sample_rate", sample_rate_in_frame, "out_sample_rate", info.sample_rate, "in_channels", channels_in_frame, "out_channels", info.channels);

                        // setup resample context
                        if (!avr) {
                                avr = avresample_alloc_context();
                                av_opt_set_int(avr,  "in_channel_layout", channel_layout_in_frame, 0);
                                av_opt_set_int(avr, "out_channel_layout", info.channel_layout, 0);
                                av_opt_set_int(avr,  "in_sample_fmt",     AV_SAMPLE_FMT_S16,     0);
                                av_opt_set_int(avr, "out_sample_fmt",     output_sample_fmt,     0); // planar not allowed here
                                av_opt_set_int(avr,  "in_sample_rate",    sample_rate_in_frame,    0);
                                av_opt_set_int(avr, "out_sample_rate",    info.sample_rate,    0);
                                av_opt_set_int(avr,  "in_channels",       channels_in_frame,    0);
                                av_opt_set_int(avr, "out_channels",       info.channels,    0);
                                avresample_open(avr);
                        }
                        int nb_samples = 0;

                        // Convert audio samples
                        nb_samples = avresample_convert(avr,    // audio resample context
                                        audio_converted->data,                  // output data pointers
                                        audio_converted->linesize[0],   // output plane size, in bytes. (0 if unknown)
                                        audio_converted->nb_samples,    // maximum number of samples that the output buffer can hold
                                        audio_frame->data,                              // input data pointers
                                        audio_frame->linesize[0],               // input plane size, in bytes (0 if unknown)
                                        audio_frame->nb_samples);               // number of input samples to convert

                        // Create a new array (to hold all resampled S16 audio samples)
                        all_resampled_samples = new int16_t[nb_samples * info.channels * (av_get_bytes_per_sample(output_sample_fmt) / av_get_bytes_per_sample(AV_SAMPLE_FMT_S16))];

                        // Copy audio samples over original samples
                        memcpy(all_resampled_samples, audio_converted->data[0], nb_samples * info.channels * av_get_bytes_per_sample(output_sample_fmt));

                        // Remove converted audio
                        free(audio_frame->data[0]); // TODO: Determine why av_free crashes on Windows
            AV_FREE_FRAME(&audio_frame);
            av_free(audio_converted->data[0]);
            AV_FREE_FRAME(&audio_converted);
                        all_queued_samples = NULL; // this array cleared with above call

                        AppendDebugMethod("FFmpegWriter::write_audio_packets (Successfully completed 1st resampling)", "nb_samples", nb_samples, "remaining_frame_samples", remaining_frame_samples, "", -1, "", -1, "", -1, "", -1);
                }

                // Loop until no more samples
                while (remaining_frame_samples > 0 || final) {
                        // Get remaining samples needed for this packet
                        int remaining_packet_samples = (audio_input_frame_size * info.channels) - audio_input_position;

                        // Determine how many samples we need
                        int diff = 0;
                        if (remaining_frame_samples >= remaining_packet_samples)
                                diff = remaining_packet_samples;
                        else if (remaining_frame_samples < remaining_packet_samples)
                                diff = remaining_frame_samples;

                        // Copy frame samples into the packet samples array
                        if (!final)
                                //TODO: Make this more sane
                                memcpy(samples + (audio_input_position * (av_get_bytes_per_sample(output_sample_fmt) / av_get_bytes_per_sample(AV_SAMPLE_FMT_S16))), all_resampled_samples + samples_position, diff * av_get_bytes_per_sample(output_sample_fmt));

                        // Increment counters
                        audio_input_position += diff;
                        samples_position += diff * (av_get_bytes_per_sample(output_sample_fmt) / av_get_bytes_per_sample(AV_SAMPLE_FMT_S16));
                        remaining_frame_samples -= diff;
                        remaining_packet_samples -= diff;

                        // Do we have enough samples to proceed?
                        if (audio_input_position < (audio_input_frame_size * info.channels) && !final)
                                // Not enough samples to encode... so wait until the next frame
                                break;

                        // Convert to planar (if needed by audio codec)
                        AVFrame *frame_final = AV_ALLOCATE_FRAME();
                        AV_RESET_FRAME(frame_final);
                        if (av_sample_fmt_is_planar(audio_codec->sample_fmt))
                        {
                                AppendDebugMethod("FFmpegWriter::write_audio_packets (2nd resampling for Planar formats)", "in_sample_fmt", output_sample_fmt, "out_sample_fmt", audio_codec->sample_fmt, "in_sample_rate", info.sample_rate, "out_sample_rate", info.sample_rate, "in_channels", info.channels, "out_channels", info.channels);

                                // setup resample context
                                if (!avr_planar) {
                                        avr_planar = avresample_alloc_context();
                                        av_opt_set_int(avr_planar,  "in_channel_layout", info.channel_layout, 0);
                                        av_opt_set_int(avr_planar, "out_channel_layout", info.channel_layout, 0);
                                        av_opt_set_int(avr_planar,  "in_sample_fmt",     output_sample_fmt,     0);
                                        av_opt_set_int(avr_planar, "out_sample_fmt",     audio_codec->sample_fmt,     0); // planar not allowed here
                                        av_opt_set_int(avr_planar,  "in_sample_rate",    info.sample_rate,    0);
                                        av_opt_set_int(avr_planar, "out_sample_rate",    info.sample_rate,    0);
                                        av_opt_set_int(avr_planar,  "in_channels",       info.channels,    0);
                                        av_opt_set_int(avr_planar, "out_channels",       info.channels,    0);
                                        avresample_open(avr_planar);
                                }

                                // Create input frame (and allocate arrays)
                                audio_frame = AV_ALLOCATE_FRAME();
                                AV_RESET_FRAME(audio_frame);
                                audio_frame->nb_samples = audio_input_position / info.channels;

                                // Create a new array
                                final_samples_planar = new int16_t[audio_frame->nb_samples * info.channels * (av_get_bytes_per_sample(output_sample_fmt) / av_get_bytes_per_sample(AV_SAMPLE_FMT_S16))];

                                // Copy audio into buffer for frame
                                memcpy(final_samples_planar, samples, audio_frame->nb_samples * info.channels * av_get_bytes_per_sample(output_sample_fmt));

                                // Fill input frame with sample data
                                avcodec_fill_audio_frame(audio_frame, info.channels, output_sample_fmt, (uint8_t *) final_samples_planar,
                                                audio_encoder_buffer_size, 0);

                                // Create output frame (and allocate arrays)
                                frame_final->nb_samples = audio_input_frame_size;
                                av_samples_alloc(frame_final->data, frame_final->linesize, info.channels, frame_final->nb_samples, audio_codec->sample_fmt, 0);

                                // Convert audio samples
                                int nb_samples = avresample_convert(avr_planar,         // audio resample context
                                                frame_final->data,                      // output data pointers
                                                frame_final->linesize[0],       // output plane size, in bytes. (0 if unknown)
                                                frame_final->nb_samples,        // maximum number of samples that the output buffer can hold
                                                audio_frame->data,                              // input data pointers
                                                audio_frame->linesize[0],               // input plane size, in bytes (0 if unknown)
                                                audio_frame->nb_samples);               // number of input samples to convert

                                // Copy audio samples over original samples
                                if (nb_samples > 0)
                                        memcpy(samples, frame_final->data[0], nb_samples * av_get_bytes_per_sample(audio_codec->sample_fmt) * info.channels);

                                // deallocate AVFrame
                                free(audio_frame->data[0]); // TODO: Determine why av_free crashes on Windows
                AV_FREE_FRAME(&audio_frame);

                                AppendDebugMethod("FFmpegWriter::write_audio_packets (Successfully completed 2nd resampling for Planar formats)", "nb_samples", nb_samples, "", -1, "", -1, "", -1, "", -1, "", -1);

                        } else {
                                // Create a new array
                                final_samples = new int16_t[audio_input_position * (av_get_bytes_per_sample(audio_codec->sample_fmt) / av_get_bytes_per_sample(AV_SAMPLE_FMT_S16))];

                                // Copy audio into buffer for frame
                                memcpy(final_samples, samples, audio_input_position * av_get_bytes_per_sample(audio_codec->sample_fmt));

                                // Init the nb_samples property
                                frame_final->nb_samples = audio_input_frame_size;

                                // Fill the final_frame AVFrame with audio (non planar)
                                avcodec_fill_audio_frame(frame_final, audio_codec->channels, audio_codec->sample_fmt, (uint8_t *) final_samples,
                                                audio_encoder_buffer_size, 0);
                        }

                        // Increment PTS (in samples)
                        write_audio_count += FFMIN(audio_input_frame_size, audio_input_position);
                        frame_final->pts = write_audio_count; // Set the AVFrame's PTS

                        // Init the packet
                        AVPacket pkt;
                        av_init_packet(&pkt);
                        pkt.data = audio_encoder_buffer;
                        pkt.size = audio_encoder_buffer_size;

                        // Set the packet's PTS prior to encoding
                        pkt.pts = pkt.dts = write_audio_count;

                        /* encode the audio samples */
                        int got_packet_ptr = 0;
                        int error_code = avcodec_encode_audio2(audio_codec, &pkt, frame_final, &got_packet_ptr);

                        /* if zero size, it means the image was buffered */
                        if (error_code == 0 && got_packet_ptr) {

                                // Since the PTS can change during encoding, set the value again.  This seems like a huge hack,
                                // but it fixes lots of PTS related issues when I do this.
                                pkt.pts = pkt.dts = write_audio_count;

                                // Scale the PTS to the audio stream timebase (which is sometimes different than the codec's timebase)
                                if (pkt.pts != AV_NOPTS_VALUE)
                                        pkt.pts = av_rescale_q(pkt.pts, audio_codec->time_base, audio_st->time_base);
                                if (pkt.dts != AV_NOPTS_VALUE)
                                        pkt.dts = av_rescale_q(pkt.dts, audio_codec->time_base, audio_st->time_base);
                                if (pkt.duration > 0)
                                        pkt.duration = av_rescale_q(pkt.duration, audio_codec->time_base, audio_st->time_base);

                                // set stream
                                pkt.stream_index = audio_st->index;
                                pkt.flags |= AV_PKT_FLAG_KEY;

                                /* write the compressed frame in the media file */
                                int error_code = av_interleaved_write_frame(oc, &pkt);
                                if (error_code < 0)
                                {
                                        AppendDebugMethod("FFmpegWriter::write_audio_packets ERROR [" + (string)av_err2str(error_code) + "]", "error_code", error_code, "", -1, "", -1, "", -1, "", -1, "", -1);
                                }
                        }

                        if (error_code < 0)
                        {
                                AppendDebugMethod("FFmpegWriter::write_audio_packets ERROR [" + (string)av_err2str(error_code) + "]", "error_code", error_code, "", -1, "", -1, "", -1, "", -1, "", -1);
                        }

                        // deallocate AVFrame
                        //free(frame_final->data[0]); // TODO: Determine why av_free crashes on Windows
            AV_FREE_FRAME(&frame_final);

                        // deallocate memory for packet
                        av_free_packet(&pkt);

                        // Reset position
                        audio_input_position = 0;
                        final = false;
                }

                // Delete arrays (if needed)
                if (all_resampled_samples) {
                        delete[] all_resampled_samples;
                        all_resampled_samples = NULL;
                }
                if (all_queued_samples) {
                        delete[] all_queued_samples;
                        all_queued_samples = NULL;
                }

        } // end task
}

// Allocate an AVFrame object
AVFrame* FFmpegWriter::allocate_avframe(PixelFormat pix_fmt, int width, int height, int *buffer_size, uint8_t *new_buffer)
{
        // Create an RGB AVFrame
        AVFrame *new_av_frame = NULL;

        // Allocate an AVFrame structure
        new_av_frame = AV_ALLOCATE_FRAME();
        if (new_av_frame == NULL)
                throw OutOfMemory("Could not allocate AVFrame", path);

        // Determine required buffer size and allocate buffer
        *buffer_size = avpicture_get_size(pix_fmt, width, height);

        // Create buffer (if not provided)
        if (!new_buffer)
        {
                // New Buffer
                new_buffer = new uint8_t[*buffer_size];
                // Attach buffer to AVFrame
                avpicture_fill((AVPicture *)new_av_frame, new_buffer, pix_fmt, width, height);
                new_av_frame->width = width;
                new_av_frame->height = height;
                new_av_frame->format = pix_fmt;
        }

        // return AVFrame
        return new_av_frame;
}

// process video frame
void FFmpegWriter::process_video_packet(tr1::shared_ptr<Frame> frame)
{
        // Determine the height & width of the source image
        int source_image_width = frame->GetWidth();
        int source_image_height = frame->GetHeight();

        // Do nothing if size is 1x1 (i.e. no image in this frame)
        if (source_image_height == 1 && source_image_width == 1)
                return;

        // Init rescalers (if not initialized yet)
        if (image_rescalers.size() == 0)
                InitScalers(source_image_width, source_image_height);

        // Get a unique rescaler (for this thread)
        SwsContext *scaler = image_rescalers[rescaler_position];
        rescaler_position++;
        if (rescaler_position == num_of_rescalers)
                rescaler_position = 0;

        #pragma omp task firstprivate(frame, scaler, source_image_width, source_image_height)
        {
                // Allocate an RGB frame & final output frame
                int bytes_source = 0;
                int bytes_final = 0;
                AVFrame *frame_source = NULL;
                const uchar *pixels = NULL;

                // Get a list of pixels from source image
                pixels = frame->GetPixels();

                // Init AVFrame for source image & final (converted image)
                frame_source = allocate_avframe(PIX_FMT_RGBA, source_image_width, source_image_height, &bytes_source, (uint8_t*) pixels);
                AVFrame *frame_final = allocate_avframe(video_codec->pix_fmt, info.width, info.height, &bytes_final, NULL);

                // Fill with data
                avpicture_fill((AVPicture *) frame_source, (uint8_t*)pixels, PIX_FMT_RGBA, source_image_width, source_image_height);
                AppendDebugMethod("FFmpegWriter::process_video_packet", "frame->number", frame->number, "bytes_source", bytes_source, "bytes_final", bytes_final, "", -1, "", -1, "", -1);

                // Resize & convert pixel format
                sws_scale(scaler, frame_source->data, frame_source->linesize, 0,
                                source_image_height, frame_final->data, frame_final->linesize);

                // Add resized AVFrame to av_frames map
                #pragma omp critical (av_frames_section)
                add_avframe(frame, frame_final);

                // Deallocate memory
                AV_FREE_FRAME(&frame_source);

        } // end task

}

// write video frame
bool FFmpegWriter::write_video_packet(tr1::shared_ptr<Frame> frame, AVFrame* frame_final)
{
        AppendDebugMethod("FFmpegWriter::write_video_packet", "frame->number", frame->number, "oc->oformat->flags & AVFMT_RAWPICTURE", oc->oformat->flags & AVFMT_RAWPICTURE, "", -1, "", -1, "", -1, "", -1);

        if (oc->oformat->flags & AVFMT_RAWPICTURE) {
                // Raw video case.
                AVPacket pkt;
                av_init_packet(&pkt);

                pkt.flags |= AV_PKT_FLAG_KEY;
                pkt.stream_index= video_st->index;
                pkt.data= (uint8_t*)frame_final->data;
                pkt.size= sizeof(AVPicture);

                // Increment PTS (in frames and scaled to the codec's timebase)
                write_video_count += av_rescale_q(1, (AVRational){info.fps.den, info.fps.num}, video_codec->time_base);
                pkt.pts = write_video_count;

                /* write the compressed frame in the media file */
                int error_code = av_interleaved_write_frame(oc, &pkt);
                if (error_code < 0)
                {
                        AppendDebugMethod("FFmpegWriter::write_video_packet ERROR [" + (string)av_err2str(error_code) + "]", "error_code", error_code, "", -1, "", -1, "", -1, "", -1, "", -1);
                        return false;
                }

                // Deallocate packet
                av_free_packet(&pkt);

        } else {

                AVPacket pkt;
                av_init_packet(&pkt);
                pkt.data = NULL;
                pkt.size = 0;
                pkt.pts = pkt.dts = AV_NOPTS_VALUE;

                // Pointer for video buffer (if using old FFmpeg version)
                uint8_t *video_outbuf = NULL;

                // Increment PTS (in frames and scaled to the codec's timebase)
                write_video_count += av_rescale_q(1, (AVRational){info.fps.den, info.fps.num}, video_codec->time_base);

                // Assign the initial AVFrame PTS from the frame counter
                frame_final->pts = write_video_count;

                /* encode the image */
                int got_packet_ptr = 0;
                int error_code = 0;
                #if LIBAVFORMAT_VERSION_MAJOR >= 54
                        // Newer versions of FFMpeg
                        error_code = avcodec_encode_video2(video_codec, &pkt, frame_final, &got_packet_ptr);

                #else
                        // Older versions of FFmpeg (much sloppier)

                        // Encode Picture and Write Frame
                        int video_outbuf_size = 200000;
                        video_outbuf = new uint8_t[200000];

                        /* encode the image */
                        int out_size = avcodec_encode_video(video_codec, video_outbuf, video_outbuf_size, frame_final);

                        /* if zero size, it means the image was buffered */
                        if (out_size > 0) {
                                if(video_codec->coded_frame->key_frame)
                                        pkt.flags |= AV_PKT_FLAG_KEY;
                                pkt.data= video_outbuf;
                                pkt.size= out_size;

                                // got data back (so encode this frame)
                                got_packet_ptr = 1;
                        }
                #endif

                /* if zero size, it means the image was buffered */
                if (error_code == 0 && got_packet_ptr) {

                        // Since the PTS can change during encoding, set the value again.  This seems like a huge hack,
                        // but it fixes lots of PTS related issues when I do this.
                        //pkt.pts = pkt.dts = write_video_count;

                        // set the timestamp
                        if (pkt.pts != AV_NOPTS_VALUE)
                                pkt.pts = av_rescale_q(pkt.pts, video_codec->time_base, video_st->time_base);
                        if (pkt.dts != AV_NOPTS_VALUE)
                                pkt.dts = av_rescale_q(pkt.dts, video_codec->time_base, video_st->time_base);
                        if (pkt.duration > 0)
                                pkt.duration = av_rescale_q(pkt.duration, video_codec->time_base, video_st->time_base);
                        pkt.stream_index = video_st->index;

                        /* write the compressed frame in the media file */
                        int error_code = av_interleaved_write_frame(oc, &pkt);
                        if (error_code < 0)
                        {
                                AppendDebugMethod("FFmpegWriter::write_video_packet ERROR [" + (string)av_err2str(error_code) + "]", "error_code", error_code, "", -1, "", -1, "", -1, "", -1, "", -1);
                                return false;
                        }
                }

                // Deallocate memory (if needed)
                if (video_outbuf)
                        delete[] video_outbuf;

                // Deallocate packet
                av_free_packet(&pkt);
        }

        // Success
        return true;
}

// Output the ffmpeg info about this format, streams, and codecs (i.e. dump format)
void FFmpegWriter::OutputStreamInfo()
{
        // output debug info
        av_dump_format(oc, 0, path.c_str(), 1);
}

// Init a collection of software rescalers (thread safe)
void FFmpegWriter::InitScalers(int source_width, int source_height)
{
        // Get the codec
        AVCodecContext *c;
        c = video_st->codec;

        // Init software rescalers vector (many of them, one for each thread)
        for (int x = 0; x < num_of_rescalers; x++)
        {
                // Init the software scaler from FFMpeg
                img_convert_ctx = sws_getContext(source_width, source_height, PIX_FMT_RGBA, info.width, info.height, c->pix_fmt, SWS_FAST_BILINEAR, NULL, NULL, NULL);

                // Add rescaler to vector
                image_rescalers.push_back(img_convert_ctx);
        }
}

// Set audio resample options
void FFmpegWriter::ResampleAudio(int sample_rate, int channels) {
        original_sample_rate = sample_rate;
        original_channels = channels;
}

// Remove & deallocate all software scalers
void FFmpegWriter::RemoveScalers()
{
        // Close all rescalers
        for (int x = 0; x < num_of_rescalers; x++)
                sws_freeContext(image_rescalers[x]);

        // Clear vector
        image_rescalers.clear();
}