Advanced search

On other websites (8015)

• react-native-ffmpeg Unrecognized option 'preset'

  8 April 2021, by Tommy Khumarga

  Below is my ffmpeg command:

  


  -y -i vidInput.mp4 -vcodec mpeg4 -b:v 1000k -b:a 48000 -preset ultrafast vidOutput.mp4

  


  And the result is:

  


  [Mon Jul 06 2020 20:42:08.171]  LOG      Unrecognized option 'preset'.
[Mon Jul 06 2020 20:42:08.172]  LOG      Error splitting the argument list:
[Mon Jul 06 2020 20:42:08.174]  LOG      Option not found


  


  Need advice...

  


• Encode PCM to MPEG-2 AAC with FFmpeg APIs

  13 August 2019, by Tank2006

  My environment is "ffmpeg version 3.4.6-0ubuntu0.18.04.1"

  I wrote a program to encode audio data into MPEG-2 AAC with reference to an official example.

  First, I simply changed the encoder value(and the full source code I wrote is here).

  if (!(output_codec = avcodec_find_encoder(AV_CODEC_ID_AAC))) {

  But FFmpeg S/PDIF encoder(spdifenc.c) returns an error “Wrong AAC file format”.

  I use avctx->profile = FF_PROFILE_MPEG2_AAC_LOW(FF_PROFILE_MPEG2_AAC_HE); but it takes no effects.

  Considering the possibility that the official binary was not compiled with the "CONFIG_ADTS_HEADER" C flag, I ran the following code directly as this:

  buf = output_packet.data;
  
  int err = init_get_bits8(&gb, buf, 7);
  
  if (get_bits(gbc, 12) != 0xfff) return AAC_AC3_PARSE_ERROR_SYNC;

  This didn’t find ADTS header "0xFFF", therefore, an encoder doesn’t seem to work as expected.

  How do I encode ffmpeg-2 aac audio with ffmpeg apis?

• extracting single frame from MediaElemet or FFmpegInterop

  13 January 2016, by Jakub Wisniewski

  I am writing app (Windows Phone 8.1 Store App) that allows user to connect to IP Camera. I am using FFmpeg Interop library for ffmpeg which allows me to play eg. rtsp streams in media element. I need now a way to somehow extract a single frame from stream or from media element.

  I have tested other application wchih allows connecting to IP cameras - IP Centcom, and they have working snapshots only for mjpeg streams as far as I now (they were not working for rtsp). Becouse of that I belive that it is impossible or at very least very hard to export frame from media element.

  I have different question - if anyone has ever used FFmpeg Interop and would like to help/explain me how could I modify/extend FFmpegInteropMSS to add method called ’GetThumbnailForStream’ that would work similary to ’GetMediaStreamSource’ but would return single frame (bitmap or jpg) instead of MediaStreamSource?

  Every help would be appreciated

  EDIT:

  I have found something;

  in MediaSampleProvider in method WriteAVPacketToStream (line 123) there is line

  auto aBuffer = ref new Platform::Array(avPacket->data, avPacket->size);

  and I belive that this is the place that stores single frame data that is needed to convert into bitmap - now since I do not know c++ too much I have a question : how can I convert it into a form that I could return via public method ?

  When returning:

  Platform::Array^

  I get

  ’FFmpegInterop::MediaSampleProvider’ : a non-value type cannot have any public data members

  EDIT2:

  Ok I am doing approprate projection to byte according to this microsoft information, now I need to check if this is correct data.