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• Issue capturing video within device specs from a USB Grabber with ffmpeg & directshow

  11 octobre 2019, par leoncvlt

  I am using a USB Grabber (this one : http://www.logilink.com/Suche/vg0001a) to capture some old VHS footage. I am using ffmpeg with directshow to do so. The device properties are as follows :

  [dshow @ 000001d57618a300] DirectShow video device options (from video devices)
  
  [dshow @ 000001d57618a300]  Pin "Capture" (alternative pin name "0")
  
  [dshow @ 000001d57618a300]   pixel_format=yuyv422  min s=640x480 fps=5 max s=640x480 fps=30
  
  [dshow @ 000001d57618a300]   pixel_format=yuyv422  min s=160x120 fps=5 max s=160x120 fps=30
  
  [dshow @ 000001d57618a300]   pixel_format=yuyv422  min s=176x144 fps=5 max s=176x144 fps=30
  
  [dshow @ 000001d57618a300]   pixel_format=yuyv422  min s=320x240 fps=5 max s=320x240 fps=30
  
  [dshow @ 000001d57618a300]   pixel_format=yuyv422  min s=352x288 fps=5 max s=352x288 fps=30
  
  [dshow @ 000001d57618a300]   pixel_format=yuyv422  min s=720x480 fps=5 max s=720x480 fps=30
  
  [dshow @ 000001d57618a300]   pixel_format=yuyv422  min s=720x576 fps=5 max s=720x576 fps=30
  
  [dshow @ 000001d57618a300]   pixel_format=yuv420p  min s=640x480 fps=5 max s=640x480 fps=30
  
  [dshow @ 000001d57618a300]   pixel_format=yuv420p  min s=160x120 fps=5 max s=160x120 fps=30
  
  [dshow @ 000001d57618a300]   pixel_format=yuv420p  min s=176x144 fps=5 max s=176x144 fps=30
  
  [dshow @ 000001d57618a300]   pixel_format=yuv420p  min s=320x240 fps=5 max s=320x240 fps=30
  
  [dshow @ 000001d57618a300]   pixel_format=yuv420p  min s=352x288 fps=5 max s=352x288 fps=30
  
  [dshow @ 000001d57618a300] Crossbar Switching Information for USB2.0 Grabber:
  
  [dshow @ 000001d57618a300]   Crossbar Output pin 0: "Video Decoder" related output pin: 1 current input pin: 0 compatible input pins: 0 1
  
  [dshow @ 000001d57618a300]   Crossbar Output pin 1: "Audio Decoder" related output pin: 0 current input pin: 4 compatible input pins: 3 4
  
  [dshow @ 000001d57618a300]   Crossbar Input pin 0 - "Video Composite" related input pin: 4
  
  [dshow @ 000001d57618a300]   Crossbar Input pin 1 - "S-Video" related input pin: 4
  
  [dshow @ 000001d57618a300]   Crossbar Input pin 2 - "Video Tuner" related input pin: 3
  
  [dshow @ 000001d57618a300]   Crossbar Input pin 3 - "Audio Tuner" related input pin: 2
  
  [dshow @ 000001d57618a300]   Crossbar Input pin 4 - "Audio Line" related input pin: 0

  I ran some tests and can capture and re-encode on the fly just fine at a variety of resolutions at both yuv420p and yuyv422 with the following command :

  ffmpeg -f dshow -pixel_format yuyv422 -video_size 720x480 -framerate 25 -i video="USB2.0 Grabber":audio="Digital Audio Interface (USB Audio Interface)" -c:v libx264 -crf 18 -aspect 4:3 -vf "yadif=1" -pix_fmt yuv420p -c:a aac -b:a 392k capture.mp4

  However, when I set -pixel_format yuyv422 -video_size 720x576 -framerate 25 which is within specs of the device, the process fails with a Too many packets buffered for output stream 0:1.. I tried increasing the buffer size with -rtbufsize and while the process starts, the video is never captured and the frame count is stuck at zero while converting - audio is captured fine.

  I thought it was the encoding not being able to keep up, but streaming the video or capturing the raw video feed with -vcodec copy I encounter the same issues.

  Using VLC to play from a capture device plays the audio only when using 720x576 as the size, while lower resolutions play fine, which make me think the issue is either with the device or me leaving out some specific directshow option.

  Any ideas ?

• avformat/matroskadec : Include webm_dash_manifest demuxer only if enabled

  20 août 2021, par Andreas Rheinhardt

  avformat/matroskadec : Include webm_dash_manifest demuxer only if enabled
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] libavformat/matroskadec.c

• avformat/matroskaenc : Pass dispositions through unchanged by default

  20 août 2021, par Andreas Rheinhardt

  avformat/matroskaenc : Pass dispositions through unchanged by default
  Up until now, the Matroska muxer did not use the dispositions it is
  
  given as-is ; instead it by default overrode the disposition of the first
  
  track of a kind (audio, video, subtitles) if no track of this kind has
  
  the default disposition set. And up until recently, it also enforced
  
  by default that no more than one track of each kind be marked as
  
  default.
  The rationale for the former is that there are lots of containers which
  
  lack the concept of default streams, so that it is not uncommon for no
  
  stream to be marked as default at all ; the rationale for the latter was
  
  that up until recently, it was dubious whether the Matroska specification
  
  allowed more than one default stream for track type (e.g. mkvmerge
  
  disallowed it). It was this point which led to the implementation of
  
  the above mentioned behaviour inspired by mkvmerge.
  Yet the Matroska specifications have changed and now explicitly allow
  
  to set more than one track of each type as default, so that the main
  
  reason of not using the dispositions as-is was rendered moot. Therefore
  
  this commit changes the default to pass the disposition through.
  The matroska-mpegts-remux FATE-test has been updated to still use the
  
  old "infer" mode so that it is still covered by FATE ; the
  
  matroska-zero-length-block test has also been updated to cover
  
  the infer_no_subs mode. The references for lots of other FATE tests
  
  needed to be updated because of a newly added FlagDefault element with
  
  value zero (whereas a FlagDefault with value 1 needn't be coded at all,
  
  as it coincided with the default value of said element).
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] doc/muxers.texi
  • [DH] libavformat/matroskaenc.c
  • [DH] libavformat/version.h
  • [DH] tests/fate/matroska.mak
  • [DH] tests/fate/wavpack.mak
  • [DH] tests/ref/fate/aac-autobsf-adtstoasc
  • [DH] tests/ref/fate/binsub-mksenc
  • [DH] tests/ref/fate/matroska-h264-remux
  • [DH] tests/ref/fate/matroska-mastering-display-metadata
  • [DH] tests/ref/fate/webm-dash-chapters
  • [DH] tests/ref/lavf-fate/av1.mkv
  • [DH] tests/ref/lavf/mka
  • [DH] tests/ref/lavf/mkv
  • [DH] tests/ref/lavf/mkv_attachment
  • [DH] tests/ref/seek/lavf-mkv