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• acces to data stream (KLV) with windows media-foundation

  20 février 2023, par hacenesh

  Is there any way to acces data stream with Windows Media Foundation ?

  


  I have a video stream that contains tree streams : Audio, video and Data stream
When I opend the file with ffmpeg I can access the three stream :

  


  

  • AVMEDIA_TYPE_AUDIO

  


  • AVMEDIA_TYPE_VIDEO

  


  • AVMEDIA_TYPE_DATA

  


  


  This image show more details about the data stream I wanted to retrieve.


  


  With windows media-foundation I can only see audio and video streams.

  


  IMFMediaSource* pVideoSource = NULL;
IMFSourceReader* pVideoReader = NULL;           
....
....
while (pVideoReader->GetStreamSelection(stmIndex, &isSelected) == S_OK) {
      printf("Stream %d is selected %d.\n", stmIndex, isSelected);

      CHECK_HR(pVideoReader->GetCurrentMediaType(stmIndex, &pStmMediaType), "Failed to get media type for selected stream.");

      std::cout << "Media type: " << GetMediaTypeDescription(pStmMediaType) << std::endl;

      GUID majorMediaType;
      pStmMediaType->GetGUID(MF_MT_MAJOR_TYPE, &majorMediaType);
      if (majorMediaType == MFMediaType_Audio) {
          std::cout << "Source audio stream index is " << stmIndex << "." << std::endl;
      }
      else if (majorMediaType == MFMediaType_Video) {
          std::cout << "Video stream index is " << stmIndex << "." << std::endl;
      }
      stmIndex++;
      SAFE_RELEASE(pStmMediaType);
  }



  


  **Output **

  


  


  Stream 0 is selected 1.
Media type : MFMediaType_Audio : MF_MT_AUDIO_AVG_BYTES_PER_SECOND=16031, MF_MT_AUDIO_BLOCK_ALIGNMENT=1, 33026EE0-E387-4582-AE0A-34A2AD3BAA18=1, MF_MT_AUDIO_NUM_CHANNELS=2, MF_MT_MAJOR_TYPE=MFMediaType_Audio, MF_MT_AUDIO_SAMPLES_PER_SECOND=48000, MF_MT_AAC_AUDIO_PROFILE_LEVEL_INDICATION=254, MF_MT_AUDIO_PREFER_WAVEFORMATEX=1, MF_MT_USER_DATA=, MF_MT_FIXED_SIZE_SAMPLES=1, MF_MT_AAC_PAYLOAD_TYPE=1, MF_MT_ALL_SAMPLES_INDEPENDENT=1, MF_MT_SAMPLE_SIZE=1, MF_MT_SUBTYPE=MFAudioFormat_AAC,
Source audio stream index is 0.
Stream 1 is selected 1.
Media type : MFMediaType_Video : MF_MT_FRAME_SIZE=W:1920 H : 1080, MF_MT_MPEG_SEQUENCE_HEADER=, MF_MT_MAJOR_TYPE=MFMediaType_Video, MF_MT_AM_FORMAT_TYPE=E06D80E3-DB46-11CF-B4D1-00805F6CBBEA, MF_MT_MPEG2_LEVEL=41, MF_MT_MPEG2_PROFILE=66, MF_MT_FIXED_SIZE_SAMPLES=1, MF_MT_FRAME_RATE=25/1, MF_MT_PIXEL_ASPECT_RATIO=1:1, MF_MT_SAMPLE_SIZE=1, MF_MT_INTERLACE_MODE=2, MF_MT_SUBTYPE=3F40F4F0-5622-4FF8-B6D8-A17A584BEE5E,
Video stream index is 1.
Source media type count : 1, is first stream selected 1.
Default output media type for source reader :
MFMediaType_Video : MF_MT_FRAME_SIZE=W:1920 H : 1080, MF_MT_MPEG_SEQUENCE_HEADER=, MF_MT_MAJOR_TYPE=MFMediaType_Video, MF_MT_AM_FORMAT_TYPE=E06D80E3-DB46-11CF-B4D1-00805F6CBBEA, MF_MT_MPEG2_LEVEL=41, MF_MT_MPEG2_PROFILE=66, MF_MT_FIXED_SIZE_SAMPLES=1, MF_MT_FRAME_RATE=25/1, MF_MT_PIXEL_ASPECT_RATIO=1:1, MF_MT_SAMPLE_SIZE=1, MF_MT_INTERLACE_MODE=2, MF_MT_SUBTYPE=3F40F4F0-5622-4FF8-B6D8-A17A584BEE5E,

  


  


  I also looked on the sample metadata. I didn't find anything.
MFSampleExtension_CaptureMetadata

  


   HRESULT hr = videoSample->GetUnknown(MFSampleExtension_CaptureMetadata, IID_IMFAttributes, (void**)&pAttributes);


  


  Result

  


  


  hr = 0xc00d36e6 : The requested attribute was not found.
access to data stream with media-foundation

  


  


• Why the source order matters on working with multiple media sources in a single AVFormatContext ?

  24 avril 2024, par Mehmet YILMAZ

  avformat_open_input() deletes the AVFormatContext* and returns -6 when the source order changes.

  


  I am trying to open multiple media sources dynamically with different(mixed) formats and codecs in a single context (AVFormatContext).

  


  My media sources are a BlackMagic DeckLink Duo SDI input as first source and an mp4 file or rtsp stream as second.

  


  When I order to open (avformat_open_input()) the source 2 (RTSP or MP4 file) at first and then open the BlackMagic DeckLink Duo, proceed as expected.

  


  But when I change the order, and first open the DeckLink and then try to open RTSP stream or MP4 file, as I inspected in the step debugger ; AVFormatContext* deleting in the av_open_input() function and it returns -6 as result.

  


  Please find the simple error reproduction code snappet below ;

  


  AVFormatContext* context{avformat_alloc_context()};
const char* url_source1{"DeckLink Duo (1)"};
const AVInputFormat* format_source1{av_find_input_format("decklink")};

const char* url_source2{"http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4"};

// Open the first media input
int result = avformat_open_input(&context, url_source1, format_source1, NULL);

if(result < 0) {
  exit(1);
}

// Open the second media input
// This function in current order deletes the context and returns -6
result = avformat_open_input(&context, url_source2, NULL, NULL);
if(result < 0) {
  exit(1);
}

// Since the context has been deleted in previous step, segmentation fault accours here!
result = avformat_find_stream_info(context, NULL);
if(result < 0) {
  exit(1);
}

std::cout << "Total number of streams: " << context->nb_streams << std::endl;



  


  But When I change the order and call the avformat_open_input() first for the mp4 file and then the DeckLink device as following it proceed as expected, no error.

  


  AVFormatContext* context{avformat_alloc_context()};
const char* url_source1{"DeckLink Duo (1)"};
const AVInputFormat* format_source1{av_find_input_format("decklink")};

const char* url_source2{"http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4"};


// Open the second media input
int result = avformat_open_input(&context, url_source2, NULL, NULL);
if(result < 0) {
  exit(1);
}


// Open the first media input
result = avformat_open_input(&context, url_source1, format_source1, NULL);

if(result < 0) {
  exit(1);
}


result = avformat_find_stream_info(context, NULL);
if(result < 0) {
  exit(1);
}

std::cout << "Total number of streams: " << context->nb_streams << std::endl;



  


• Parse dynamic mpd file with Media Source Extensions

  17 février 2023, par FrankC

  I just started learning about adaptive streaming, and currently I'm working on a project that needs showing a live video. In order to control some of the elements in mpd file, I determined to use MSE instead of dash.js. I refer to the code at the following URL :https://learn.microsoft.com/en-us/previous-versions/windows/internet-explorer/ie-developer/samples/dn551368(v=vs.85)
But I found out that there is no "Initialization" tag or "range" attribute in my mpd file. I don't find any relative attribute as well. By the way I'm use nginx-rtmp + ffmpeg to generate dash file.
So here is my dash file looks like

  


  &lt;?xml version="1.0"?>&#xA; &#xA;  <period start="PT0S">&#xA;    &#xA;      &#xA;        &#xA;          <segmenttimeline>&#xA;             <s t="0" d="10000"></s>&#xA;             <s t="10000" d="10000"></s>&#xA;             <s t="20000" d="5000"></s>&#xA;             <s t="25000" d="10000"></s>&#xA;          </segmenttimeline>&#xA;        &#xA;      &#xA;    &#xA;  </period>&#xA;&#xA;

  


  My question is :
1.Did I have any missing parameters in using ffmpeg or nginx-rtmp resulting in losting tag in mpd file ?
2.Or there is other way to setup "Initialization"/"range" attribute and let my program work ?
3.I also curious about why my mpd file doesn't have a baseURL element ?

  


  ※My mpd file works fine with dash.js, I can see the video properly

  


  THANKS A LOT