Recherche avancée

Sur d’autres sites (9285)

• Revision 4b0b43632b : Pass B_PREDICTION_MODE to intra4x4_predict Use the correct type when calling an

  2 août 2012, par Johann

  Changed Paths : Modify /vp8/common/reconintra4x4.c Modify /vp8/common/rtcd_defs.sh Modify /vp8/decoder/decodframe.c Modify /vp8/decoder/threading.c Modify /vp8/encoder/pickinter.c Modify /vp8/encoder/rdopt.c Pass B_PREDICTION_MODE to intra4x4_predict Use the correct type when calling (...)

• ffmpeg : Render a two-pass MP4 timelapse video from a glob of JPEG images

  20 mai 2024, par algalg

  In bash on an Ubuntu 22 LTS system, I have this line to make a timelapse video file from hundreds of collected JPEG images in a folder.

  


  ffmpeg -r 25 \
  -pattern_type glob -i "/some/path/input/*.jpg" \
  -vf "pad=ceil(iw/2)*2:ceil(ih/2)*2" \
  -pix_fmt yuvj420p -preset veryslow -qp 0 \
  -movflags +faststart \
  "/some/path/output/render.mp4"


  


  The input JPEGs are 4K, so the resulting video file in that same resolution, and at high quality (which is desired), renders to a very large video file ( 250GB).

  


  Through trial and error, I've needed to add the -vf padding to avoid potential "height not divisible by 2" crashes, and set the pixel format to explicitly use jpeg full colour range yuvj420p because some of the original JPEG images were making ffmpeg complain about that.

  


  And since the goal is to eventually use these renders for streaming, -movflags +faststart was also added.

  


  It's all seeming to work very well, but just producing very large high quality video files :

  


  So to try address the filesize problem, but sticking to h264, I started reading some tutorials/docs (this one for example) that mentioned running two passes to compress the video more effectively.

  


  This sounded promising, and so to do this all in one step, rather than rendering a video and re-rendering that in two passes to better compress it) I tried this :

  


  ffmpeg -y -r 25 \
  -pattern_type glob -i "/some/path/input/*.jpg" \
  -vf "pad=ceil(iw/2)*2:ceil(ih/2)*2" \
  -pix_fmt yuvj420p -preset veryslow -qp 0 \
  -movflags +faststart \
  -pass 1 -f null /dev/null &&
ffmpeg -r 25 \
  -pattern_type glob -i "/some/path/input/*.jpg" \
  -vf "pad=ceil(iw/2)*2:ceil(ih/2)*2" \
  -pix_fmt yuvj420p -preset veryslow -qp 0 \
  -movflags +faststart \
  -pass 2 -f mp4 "/some/path/output/render.mp4"


  


  But ffmpeg seems to freak out about the inputs then :

  


  [image2 @ 0x55674a3bc440] Could not open file : /some/path/input/*.jpg
[image2 @ 0x55674a3bc440] Could not find codec parameters for stream 0 (Video: mjpeg, none(bt470bg/unknown/unknown)): unspecified size
Consider increasing the value for the 'analyzeduration' (0) and 'probesize' (5000000) options
Input #0, image2, from '/some/path/input/*.jpg':
  Duration: 00:00:00.04, start: 0.000000, bitrate: N/A
  Stream #0:0: Video: mjpeg, none(bt470bg/unknown/unknown), 25 fps, 25 tbr, 25 tbn, 25 tbc
Output #0, mp4, to '/dev/null':
Output file #0 does not contain any stream


  


  I've tried searching around a bit for if it's even possible to do two passes with the globbing input method, but haven't had much luck in finding any documentation or help about it.

  


  So asking here if anyone has any insights ? What am I doing wrong ? Is this possible ?

  


• ffmpeg_filter : Pass command line -threads X to filtergraph

  24 octobre 2013, par Michael Niedermayer

  ffmpeg_filter : Pass command line -threads X to filtergraph
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] ffmpeg_filter.c