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FFmpeg.Autogen Wrapper : Issue with Zero-Sized Atom Boxes in MP4 Output
11 juin, par Alexander JanssonI just started learning ffmpeg using ffmpeg.autogen wrapper version 5.1 in c#, and ffmpeg shared libs version 5.1. Im trying to facilitate a class which screenrecords using gdigrab and produces streamable mp4 to a/an buffer/event. Everything seems to work as suposed to with no error except that the outputstream produces atom boxes with 0 in size thus small file size aswell, no data seems to be produced in the boxes, the "debug test mp4 file" is analyzed with MP4Box and the box info is provided in the thread.


To be more specific why does this code produce empty atomboxes, is someone able to make the data produced actually contain any frame data from the gdigrab editing my code ?


`code :


public unsafe class ScreenStreamer : IDisposable
 {
 private readonly AVCodec* productionCodec;
 private readonly AVCodec* screenCaptureAVCodec;
 private readonly AVCodecContext* productionAVCodecContext;
 private readonly AVFormatContext* productionFormatContext;
 private readonly AVCodecContext* screenCaptureAVCodecContext;
 private readonly AVDictionary* productionAVCodecOptions;
 private readonly AVInputFormat* screenCaptureInputFormat;
 private readonly AVFormatContext* screenCaptureInputFormatContext;
 private readonly int gDIGrabVideoStreamIndex;
 private readonly System.Drawing.Size screenBounds;
 private readonly int _produceAtleastAmount;
 public EventHandler OnNewVideoDataProduced;
 private MemoryStream unsafeToManagedBridgeBuffer;
 private CancellationTokenSource cancellationTokenSource;
 private Task recorderTask;

 public ScreenStreamer(int fps, int bitrate, int screenIndex, int produceAtleastAmount = 1000)
 {
 ffmpeg.avdevice_register_all();
 ffmpeg.avformat_network_init();
 recorderTask = Task.CompletedTask;
 cancellationTokenSource = new CancellationTokenSource();
 unsafeToManagedBridgeBuffer = new MemoryStream();
 _produceAtleastAmount = produceAtleastAmount;

 // Allocate and initialize production codec and context
 productionCodec = ffmpeg.avcodec_find_encoder(AVCodecID.AV_CODEC_ID_H264);
 if (productionCodec == null) throw new ApplicationException("Could not find encoder for codec ID H264.");

 productionAVCodecContext = ffmpeg.avcodec_alloc_context3(productionCodec);
 if (productionAVCodecContext == null) throw new ApplicationException("Could not allocate video codec context.");

 // Set codec parameters
 screenBounds = RetrieveScreenBounds(screenIndex);
 productionAVCodecContext->width = screenBounds.Width;
 productionAVCodecContext->height = screenBounds.Height;
 productionAVCodecContext->time_base = new AVRational() { den = fps, num = 1 };
 productionAVCodecContext->pix_fmt = AVPixelFormat.AV_PIX_FMT_YUV420P;
 productionAVCodecContext->bit_rate = bitrate;

 int result = ffmpeg.av_opt_set(productionAVCodecContext->priv_data, "preset", "veryfast", 0);
 if (result != 0)
 {
 throw new ApplicationException($"Failed to set options with error code {result}.");
 }

 // Open codec
 fixed (AVDictionary** pm = &productionAVCodecOptions)
 {
 result = ffmpeg.av_dict_set(pm, "movflags", "frag_keyframe+empty_moov+default_base_moof", 0);
 if (result < 0)
 {
 throw new ApplicationException($"Failed to set dictionary with error code {result}.");
 }

 result = ffmpeg.avcodec_open2(productionAVCodecContext, productionCodec, pm);
 if (result < 0)
 {
 throw new ApplicationException($"Failed to open codec with error code {result}.");
 }
 }

 // Allocate and initialize screen capture codec and context
 screenCaptureInputFormat = ffmpeg.av_find_input_format("gdigrab");
 if (screenCaptureInputFormat == null) throw new ApplicationException("Could not find input format gdigrab.");

 fixed (AVFormatContext** ps = &screenCaptureInputFormatContext)
 {
 result = ffmpeg.avformat_open_input(ps, "desktop", screenCaptureInputFormat, null);
 if (result < 0)
 {
 throw new ApplicationException($"Failed to open input with error code {result}.");
 }

 result = ffmpeg.avformat_find_stream_info(screenCaptureInputFormatContext, null);
 if (result < 0)
 {
 throw new ApplicationException($"Failed to find stream info with error code {result}.");
 }
 }

 gDIGrabVideoStreamIndex = -1;
 for (int i = 0; i < screenCaptureInputFormatContext->nb_streams; i++)
 {
 if (screenCaptureInputFormatContext->streams[i]->codecpar->codec_type == AVMediaType.AVMEDIA_TYPE_VIDEO)
 {
 gDIGrabVideoStreamIndex = i;
 break;
 }
 }

 if (gDIGrabVideoStreamIndex < 0)
 {
 throw new ApplicationException("Failed to find video stream in input.");
 }

 AVCodecParameters* codecParameters = screenCaptureInputFormatContext->streams[gDIGrabVideoStreamIndex]->codecpar;
 screenCaptureAVCodec = ffmpeg.avcodec_find_decoder(codecParameters->codec_id);
 if (screenCaptureAVCodec == null)
 {
 throw new ApplicationException("Could not find decoder for screen capture.");
 }

 screenCaptureAVCodecContext = ffmpeg.avcodec_alloc_context3(screenCaptureAVCodec);
 if (screenCaptureAVCodecContext == null)
 {
 throw new ApplicationException("Could not allocate screen capture codec context.");
 }

 result = ffmpeg.avcodec_parameters_to_context(screenCaptureAVCodecContext, codecParameters);
 if (result < 0)
 {
 throw new ApplicationException($"Failed to copy codec parameters to context with error code {result}.");
 }

 result = ffmpeg.avcodec_open2(screenCaptureAVCodecContext, screenCaptureAVCodec, null);
 if (result < 0)
 {
 throw new ApplicationException($"Failed to open screen capture codec with error code {result}.");
 }
 }

 public void Start()
 {
 recorderTask = Task.Run(() =>
 {
 AVPacket* packet = ffmpeg.av_packet_alloc();
 AVFrame* rawFrame = ffmpeg.av_frame_alloc();
 AVFrame* compatibleFrame = null;
 byte* dstBuffer = null;

 try
 {
 while (!cancellationTokenSource.Token.IsCancellationRequested)
 {
 if (ffmpeg.av_read_frame(screenCaptureInputFormatContext, packet) >= 0)
 {
 if (packet->stream_index == gDIGrabVideoStreamIndex)
 {
 int response = ffmpeg.avcodec_send_packet(screenCaptureAVCodecContext, packet);
 if (response < 0)
 {
 throw new ApplicationException($"Error while sending a packet to the decoder: {response}");
 }

 response = ffmpeg.avcodec_receive_frame(screenCaptureAVCodecContext, rawFrame);
 if (response == ffmpeg.AVERROR(ffmpeg.EAGAIN) || response == ffmpeg.AVERROR_EOF)
 {
 continue;
 }
 else if (response < 0)
 {
 throw new ApplicationException($"Error while receiving a frame from the decoder: {response}");
 }

 compatibleFrame = ConvertToCompatiblePixelFormat(rawFrame, out dstBuffer);

 response = ffmpeg.avcodec_send_frame(productionAVCodecContext, compatibleFrame);
 if (response < 0)
 {
 throw new ApplicationException($"Error while sending a frame to the encoder: {response}");
 }

 while (response >= 0)
 {
 response = ffmpeg.avcodec_receive_packet(productionAVCodecContext, packet);
 if (response == ffmpeg.AVERROR(ffmpeg.EAGAIN) || response == ffmpeg.AVERROR_EOF)
 {
 break;
 }
 else if (response < 0)
 {
 throw new ApplicationException($"Error while receiving a packet from the encoder: {response}");
 }

 using var packetStream = new UnmanagedMemoryStream(packet->data, packet->size);
 packetStream.CopyTo(unsafeToManagedBridgeBuffer);
 byte[] managedBytes = unsafeToManagedBridgeBuffer.ToArray();
 OnNewVideoDataProduced?.Invoke(this, managedBytes);
 unsafeToManagedBridgeBuffer.SetLength(0);
 }
 }
 }
 ffmpeg.av_packet_unref(packet);
 ffmpeg.av_frame_unref(rawFrame);
 if (compatibleFrame != null)
 {
 ffmpeg.av_frame_unref(compatibleFrame);
 ffmpeg.av_free(dstBuffer);
 }
 }
 }
 finally
 {
 ffmpeg.av_packet_free(&packet);
 ffmpeg.av_frame_free(&rawFrame);
 if (compatibleFrame != null)
 {
 ffmpeg.av_frame_free(&compatibleFrame);
 }
 }
 });
 }

 public AVFrame* ConvertToCompatiblePixelFormat(AVFrame* srcFrame, out byte* dstBuffer)
 {
 AVFrame* dstFrame = ffmpeg.av_frame_alloc();
 int buffer_size = ffmpeg.av_image_get_buffer_size(productionAVCodecContext->pix_fmt, productionAVCodecContext->width, productionAVCodecContext->height, 1);
 byte_ptrArray4 dstData = new byte_ptrArray4();
 int_array4 dstLinesize = new int_array4();
 dstBuffer = (byte*)ffmpeg.av_malloc((ulong)buffer_size);
 ffmpeg.av_image_fill_arrays(ref dstData, ref dstLinesize, dstBuffer, productionAVCodecContext->pix_fmt, productionAVCodecContext->width, productionAVCodecContext->height, 1);

 dstFrame->format = (int)productionAVCodecContext->pix_fmt;
 dstFrame->width = productionAVCodecContext->width;
 dstFrame->height = productionAVCodecContext->height;
 dstFrame->data.UpdateFrom(dstData);
 dstFrame->linesize.UpdateFrom(dstLinesize);

 SwsContext* swsCtx = ffmpeg.sws_getContext(
 srcFrame->width, srcFrame->height, (AVPixelFormat)srcFrame->format,
 productionAVCodecContext->width, productionAVCodecContext->height, productionAVCodecContext->pix_fmt,
 ffmpeg.SWS_BILINEAR, null, null, null);

 if (swsCtx == null)
 {
 throw new ApplicationException("Could not initialize the conversion context.");
 }

 ffmpeg.sws_scale(swsCtx, srcFrame->data, srcFrame->linesize, 0, srcFrame->height, dstFrame->data, dstFrame->linesize);
 ffmpeg.sws_freeContext(swsCtx);
 return dstFrame;
 }

 private System.Drawing.Size RetrieveScreenBounds(int screenIndex)
 {
 return new System.Drawing.Size(1920, 1080);
 }

 public void Dispose()
 {
 cancellationTokenSource?.Cancel();
 recorderTask?.Wait();
 cancellationTokenSource?.Dispose();
 recorderTask?.Dispose();
 unsafeToManagedBridgeBuffer?.Dispose();

 fixed (AVCodecContext** p = &productionAVCodecContext)
 {
 if (*p != null)
 {
 ffmpeg.avcodec_free_context(p);
 }
 }
 fixed (AVCodecContext** p = &screenCaptureAVCodecContext)
 {
 if (*p != null)
 {
 ffmpeg.avcodec_free_context(p);
 }
 }

 if (productionFormatContext != null)
 {
 ffmpeg.avformat_free_context(productionFormatContext);
 }

 if (screenCaptureInputFormatContext != null)
 {
 ffmpeg.avformat_free_context(screenCaptureInputFormatContext);
 }

 if (productionAVCodecOptions != null)
 {
 fixed (AVDictionary** p = &productionAVCodecOptions)
 {
 ffmpeg.av_dict_free(p);
 }
 }
 }
 }


I call Start method and wait 8 econds, out of scope I write the bytes to an mp4 file without using the write trailer just to debug the atomboxes. and the mp4 debugging box output I got :


(Full OUTPUT)
https://pastebin.com/xkM4MfG7



(Not full)




"
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-
FFmpeg.Autogen : Issue with Zero-Sized Atom Boxes in MP4 Output
12 juin, par Alexander JanssonI just started learning ffmpeg using ffmpeg.autogen wrapper version 5.1 in c#, and ffmpeg shared libs version 5.1. Im trying to facilitate a class which screenrecords using gdigrab and produces streamable mp4 to a/an buffer/event. Everything seems to work as suposed to with no error except that the outputstream produces atom boxes with 0 in size thus small file size aswell, no data seems to be produced in the boxes, the "debug test mp4 file" is analyzed with MP4Box and the box info is provided in the thread.


To be more specific why does this code produce empty atomboxes, is someone able to make the data produced actually contain any frame data from the gdigrab editing my code ?


`code :


public unsafe class ScreenStreamer : IDisposable
 {
 private readonly AVCodec* productionCodec;
 private readonly AVCodec* screenCaptureAVCodec;
 private readonly AVCodecContext* productionAVCodecContext;
 private readonly AVFormatContext* productionFormatContext;
 private readonly AVCodecContext* screenCaptureAVCodecContext;
 private readonly AVDictionary* productionAVCodecOptions;
 private readonly AVInputFormat* screenCaptureInputFormat;
 private readonly AVFormatContext* screenCaptureInputFormatContext;
 private readonly int gDIGrabVideoStreamIndex;
 private readonly System.Drawing.Size screenBounds;
 private readonly int _produceAtleastAmount;
 public EventHandler OnNewVideoDataProduced;
 private MemoryStream unsafeToManagedBridgeBuffer;
 private CancellationTokenSource cancellationTokenSource;
 private Task recorderTask;

 public ScreenStreamer(int fps, int bitrate, int screenIndex, int produceAtleastAmount = 1000)
 {
 ffmpeg.avdevice_register_all();
 ffmpeg.avformat_network_init();
 recorderTask = Task.CompletedTask;
 cancellationTokenSource = new CancellationTokenSource();
 unsafeToManagedBridgeBuffer = new MemoryStream();
 _produceAtleastAmount = produceAtleastAmount;

 // Allocate and initialize production codec and context
 productionCodec = ffmpeg.avcodec_find_encoder(AVCodecID.AV_CODEC_ID_H264);
 if (productionCodec == null) throw new ApplicationException("Could not find encoder for codec ID H264.");

 productionAVCodecContext = ffmpeg.avcodec_alloc_context3(productionCodec);
 if (productionAVCodecContext == null) throw new ApplicationException("Could not allocate video codec context.");

 // Set codec parameters
 screenBounds = RetrieveScreenBounds(screenIndex);
 productionAVCodecContext->width = screenBounds.Width;
 productionAVCodecContext->height = screenBounds.Height;
 productionAVCodecContext->time_base = new AVRational() { den = fps, num = 1 };
 productionAVCodecContext->pix_fmt = AVPixelFormat.AV_PIX_FMT_YUV420P;
 productionAVCodecContext->bit_rate = bitrate;

 int result = ffmpeg.av_opt_set(productionAVCodecContext->priv_data, "preset", "veryfast", 0);
 if (result != 0)
 {
 throw new ApplicationException($"Failed to set options with error code {result}.");
 }

 // Open codec
 fixed (AVDictionary** pm = &productionAVCodecOptions)
 {
 result = ffmpeg.av_dict_set(pm, "movflags", "frag_keyframe+empty_moov+default_base_moof", 0);
 if (result < 0)
 {
 throw new ApplicationException($"Failed to set dictionary with error code {result}.");
 }

 result = ffmpeg.avcodec_open2(productionAVCodecContext, productionCodec, pm);
 if (result < 0)
 {
 throw new ApplicationException($"Failed to open codec with error code {result}.");
 }
 }

 // Allocate and initialize screen capture codec and context
 screenCaptureInputFormat = ffmpeg.av_find_input_format("gdigrab");
 if (screenCaptureInputFormat == null) throw new ApplicationException("Could not find input format gdigrab.");

 fixed (AVFormatContext** ps = &screenCaptureInputFormatContext)
 {
 result = ffmpeg.avformat_open_input(ps, "desktop", screenCaptureInputFormat, null);
 if (result < 0)
 {
 throw new ApplicationException($"Failed to open input with error code {result}.");
 }

 result = ffmpeg.avformat_find_stream_info(screenCaptureInputFormatContext, null);
 if (result < 0)
 {
 throw new ApplicationException($"Failed to find stream info with error code {result}.");
 }
 }

 gDIGrabVideoStreamIndex = -1;
 for (int i = 0; i < screenCaptureInputFormatContext->nb_streams; i++)
 {
 if (screenCaptureInputFormatContext->streams[i]->codecpar->codec_type == AVMediaType.AVMEDIA_TYPE_VIDEO)
 {
 gDIGrabVideoStreamIndex = i;
 break;
 }
 }

 if (gDIGrabVideoStreamIndex < 0)
 {
 throw new ApplicationException("Failed to find video stream in input.");
 }

 AVCodecParameters* codecParameters = screenCaptureInputFormatContext->streams[gDIGrabVideoStreamIndex]->codecpar;
 screenCaptureAVCodec = ffmpeg.avcodec_find_decoder(codecParameters->codec_id);
 if (screenCaptureAVCodec == null)
 {
 throw new ApplicationException("Could not find decoder for screen capture.");
 }

 screenCaptureAVCodecContext = ffmpeg.avcodec_alloc_context3(screenCaptureAVCodec);
 if (screenCaptureAVCodecContext == null)
 {
 throw new ApplicationException("Could not allocate screen capture codec context.");
 }

 result = ffmpeg.avcodec_parameters_to_context(screenCaptureAVCodecContext, codecParameters);
 if (result < 0)
 {
 throw new ApplicationException($"Failed to copy codec parameters to context with error code {result}.");
 }

 result = ffmpeg.avcodec_open2(screenCaptureAVCodecContext, screenCaptureAVCodec, null);
 if (result < 0)
 {
 throw new ApplicationException($"Failed to open screen capture codec with error code {result}.");
 }
 }

 public void Start()
 {
 recorderTask = Task.Run(() =>
 {
 AVPacket* packet = ffmpeg.av_packet_alloc();
 AVFrame* rawFrame = ffmpeg.av_frame_alloc();
 AVFrame* compatibleFrame = null;
 byte* dstBuffer = null;

 try
 {
 while (!cancellationTokenSource.Token.IsCancellationRequested)
 {
 if (ffmpeg.av_read_frame(screenCaptureInputFormatContext, packet) >= 0)
 {
 if (packet->stream_index == gDIGrabVideoStreamIndex)
 {
 int response = ffmpeg.avcodec_send_packet(screenCaptureAVCodecContext, packet);
 if (response < 0)
 {
 throw new ApplicationException($"Error while sending a packet to the decoder: {response}");
 }

 response = ffmpeg.avcodec_receive_frame(screenCaptureAVCodecContext, rawFrame);
 if (response == ffmpeg.AVERROR(ffmpeg.EAGAIN) || response == ffmpeg.AVERROR_EOF)
 {
 continue;
 }
 else if (response < 0)
 {
 throw new ApplicationException($"Error while receiving a frame from the decoder: {response}");
 }

 compatibleFrame = ConvertToCompatiblePixelFormat(rawFrame, out dstBuffer);

 response = ffmpeg.avcodec_send_frame(productionAVCodecContext, compatibleFrame);
 if (response < 0)
 {
 throw new ApplicationException($"Error while sending a frame to the encoder: {response}");
 }

 while (response >= 0)
 {
 response = ffmpeg.avcodec_receive_packet(productionAVCodecContext, packet);
 if (response == ffmpeg.AVERROR(ffmpeg.EAGAIN) || response == ffmpeg.AVERROR_EOF)
 {
 break;
 }
 else if (response < 0)
 {
 throw new ApplicationException($"Error while receiving a packet from the encoder: {response}");
 }

 using var packetStream = new UnmanagedMemoryStream(packet->data, packet->size);
 packetStream.CopyTo(unsafeToManagedBridgeBuffer);
 byte[] managedBytes = unsafeToManagedBridgeBuffer.ToArray();
 OnNewVideoDataProduced?.Invoke(this, managedBytes);
 unsafeToManagedBridgeBuffer.SetLength(0);
 }
 }
 }
 ffmpeg.av_packet_unref(packet);
 ffmpeg.av_frame_unref(rawFrame);
 if (compatibleFrame != null)
 {
 ffmpeg.av_frame_unref(compatibleFrame);
 ffmpeg.av_free(dstBuffer);
 }
 }
 }
 finally
 {
 ffmpeg.av_packet_free(&packet);
 ffmpeg.av_frame_free(&rawFrame);
 if (compatibleFrame != null)
 {
 ffmpeg.av_frame_free(&compatibleFrame);
 }
 }
 });
 }

 public AVFrame* ConvertToCompatiblePixelFormat(AVFrame* srcFrame, out byte* dstBuffer)
 {
 AVFrame* dstFrame = ffmpeg.av_frame_alloc();
 int buffer_size = ffmpeg.av_image_get_buffer_size(productionAVCodecContext->pix_fmt, productionAVCodecContext->width, productionAVCodecContext->height, 1);
 byte_ptrArray4 dstData = new byte_ptrArray4();
 int_array4 dstLinesize = new int_array4();
 dstBuffer = (byte*)ffmpeg.av_malloc((ulong)buffer_size);
 ffmpeg.av_image_fill_arrays(ref dstData, ref dstLinesize, dstBuffer, productionAVCodecContext->pix_fmt, productionAVCodecContext->width, productionAVCodecContext->height, 1);

 dstFrame->format = (int)productionAVCodecContext->pix_fmt;
 dstFrame->width = productionAVCodecContext->width;
 dstFrame->height = productionAVCodecContext->height;
 dstFrame->data.UpdateFrom(dstData);
 dstFrame->linesize.UpdateFrom(dstLinesize);

 SwsContext* swsCtx = ffmpeg.sws_getContext(
 srcFrame->width, srcFrame->height, (AVPixelFormat)srcFrame->format,
 productionAVCodecContext->width, productionAVCodecContext->height, productionAVCodecContext->pix_fmt,
 ffmpeg.SWS_BILINEAR, null, null, null);

 if (swsCtx == null)
 {
 throw new ApplicationException("Could not initialize the conversion context.");
 }

 ffmpeg.sws_scale(swsCtx, srcFrame->data, srcFrame->linesize, 0, srcFrame->height, dstFrame->data, dstFrame->linesize);
 ffmpeg.sws_freeContext(swsCtx);
 return dstFrame;
 }

 private System.Drawing.Size RetrieveScreenBounds(int screenIndex)
 {
 return new System.Drawing.Size(1920, 1080);
 }

 public void Dispose()
 {
 cancellationTokenSource?.Cancel();
 recorderTask?.Wait();
 cancellationTokenSource?.Dispose();
 recorderTask?.Dispose();
 unsafeToManagedBridgeBuffer?.Dispose();

 fixed (AVCodecContext** p = &productionAVCodecContext)
 {
 if (*p != null)
 {
 ffmpeg.avcodec_free_context(p);
 }
 }
 fixed (AVCodecContext** p = &screenCaptureAVCodecContext)
 {
 if (*p != null)
 {
 ffmpeg.avcodec_free_context(p);
 }
 }

 if (productionFormatContext != null)
 {
 ffmpeg.avformat_free_context(productionFormatContext);
 }

 if (screenCaptureInputFormatContext != null)
 {
 ffmpeg.avformat_free_context(screenCaptureInputFormatContext);
 }

 if (productionAVCodecOptions != null)
 {
 fixed (AVDictionary** p = &productionAVCodecOptions)
 {
 ffmpeg.av_dict_free(p);
 }
 }
 }
 }


I call Start method and wait 8 econds, out of scope I write the bytes to an mp4 file without using the write trailer just to debug the atomboxes. and the mp4 debugging box output I got :


(Full OUTPUT)
https://pastebin.com/xkM4MfG7



(Not full)




"
<boxes>
<uuidbox size="0" type="uuid" uuid="{00000000-00000000-00000000-00000000}" specification="unknown" container="unknown">
</uuidbox>
<trackreferencetypebox size="0" type="cdsc" specification="p12" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="hint" specification="p12" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="font" specification="p12" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="hind" specification="p12" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="vdep" specification="p12" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="vplx" specification="p12" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="subt" specification="p12" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="thmb" specification="p12" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="mpod" specification="p14" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="dpnd" specification="p14" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="sync" specification="p14" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="ipir" specification="p14" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="sbas" specification="p15" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="scal" specification="p15" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="tbas" specification="p15" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="sabt" specification="p15" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="oref" specification="p15" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="adda" specification="p12" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
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<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="iloc" specification="p12" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="avcp" specification="p15" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="swto" specification="p15" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="swfr" specification="p15" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="chap" specification="apple" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="tmcd" specification="apple" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="cdep" specification="apple" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="scpt" specification="apple" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="ssrc" specification="apple" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<trackreferencetypebox size="0" type="lyra" specification="apple" container="tref">
<trackreferenceentry trackid=""></trackreferenceentry>
</trackreferencetypebox>
<itemreferencebox size="0" type="tbas" specification="p12" container="iref">
<itemreferenceboxentry itemid=""></itemreferenceboxentry>
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<itemreferenceboxentry itemid=""></itemreferenceboxentry>
</itemreferencebox>
<itemreferencebox size="0" type="fdel" specification="p12" container="iref">
<itemreferenceboxentry itemid=""></itemreferenceboxentry>
</itemreferencebox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p12" container="stbl traf">
<rollrecoveryentry></rollrecoveryentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p12" container="stbl traf">
<audioprerollentry></audioprerollentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p12" container="stbl traf">
<visualrandomaccessentry></visualrandomaccessentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<cencsampleencryptiongroupentry isencrypted="" kid=""></cencsampleencryptiongroupentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<operatingpointsinformation>
 <profiletierlevel></profiletierlevel>
<operatingpoint minpicwidth="" minpicheight="" maxpicwidth="" maxpicheight="" maxchromaformat="" maxbitdepth="" avgframerate="" constantframerate="" maxbitrate="" avgbitrate=""></operatingpoint>

</operatingpointsinformation>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<layerinformation>
<layerinfoitem></layerinfoitem>
</layerinformation>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<tileregiongroupentry tilegroup="" independent="" x="" y="" w="" h="">
<tileregiondependency tileid=""></tileregiondependency>
</tileregiongroupentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<nalumap rle="">
<nalumapentry groupid=""></nalumapentry>
</nalumap>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p12" container="stbl traf">
<temporallevelentry></temporallevelentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p12" container="stbl traf">
<defaultsamplegroupdescriptionentry size=""></defaultsamplegroupdescriptionentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p12" container="stbl traf">
<defaultsamplegroupdescriptionentry size=""></defaultsamplegroupdescriptionentry>
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<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p12" container="stbl traf">
<sapentry></sapentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<defaultsamplegroupdescriptionentry size=""></defaultsamplegroupdescriptionentry>
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<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<defaultsamplegroupdescriptionentry size=""></defaultsamplegroupdescriptionentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<defaultsamplegroupdescriptionentry size=""></defaultsamplegroupdescriptionentry>
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<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<defaultsamplegroupdescriptionentry size=""></defaultsamplegroupdescriptionentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<defaultsamplegroupdescriptionentry size=""></defaultsamplegroupdescriptionentry>
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<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<defaultsamplegroupdescriptionentry size=""></defaultsamplegroupdescriptionentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<defaultsamplegroupdescriptionentry size=""></defaultsamplegroupdescriptionentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<defaultsamplegroupdescriptionentry size=""></defaultsamplegroupdescriptionentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<syncsamplegroupentry></syncsamplegroupentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<defaultsamplegroupdescriptionentry size=""></defaultsamplegroupdescriptionentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<defaultsamplegroupdescriptionentry size=""></defaultsamplegroupdescriptionentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<defaultsamplegroupdescriptionentry size=""></defaultsamplegroupdescriptionentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="p15" container="stbl traf">
<subpictureorderentry refs=""></subpictureorderentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="3gpp" container="stbl traf">
<defaultsamplegroupdescriptionentry size=""></defaultsamplegroupdescriptionentry>
</samplegroupdescriptionbox>
<samplegroupdescriptionbox size="0" type="sgpd" version="0" flags="0" specification="3gpp" container="stbl traf">
<defaultsamplegroupdescriptionentry size=""></defaultsamplegroupdescriptionentry>
</samplegroupdescriptionbox>
<sampledescriptionentrybox size="0" type="GNRM" specification="unknown" container="stsd" extensiondatasize="0">
</sampledescriptionentrybox>
<visualsampledescriptionbox size="0" type="GNRV" specification="unknown" container="stsd" version="0" revision="0" vendor="0" temporalquality="0" spacialquality="0" width="0" height="0" horizontalresolution="4718592" verticalresolution="4718592" compressorname="" bitdepth="24">
</visualsampledescriptionbox>
<audiosampledescriptionbox size="0" type="GNRA" specification="unknown" container="stsd" version="0" revision="0" vendor="0" channelcount="2" bitspersample="16" samplerate="0">
</audiosampledescriptionbox>
<trackgrouptypebox size="0" type="msrc" version="0" flags="0" specification="p12" container="trgr">
</trackgrouptypebox>
<trackgrouptypebox size="0" type="ster" version="0" flags="0" specification="p12" container="trgr">
</trackgrouptypebox>
<trackgrouptypebox size="0" type="cstg" version="0" flags="0" specification="p15" container="trgr">
</trackgrouptypebox>
<freespacebox size="0" type="free" specification="p12" container="*">
</freespacebox>
<freespacebox size="0" type="free" specification="p12" container="*">
</freespacebox>
<mediadatabox size="0" type="mdat" specification="p12" container="file">
</mediadatabox>
<mediadatabox size="0" type="mdat" specification="p12" container="meta">
"
</mediadatabox></boxes>

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