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• lavc/mediacodecdec : set codec profile and level from extradata for H264+HEVC

  13 décembre 2021, par sfan5

  lavc/mediacodecdec : set codec profile and level from extradata for H264+HEVC
  This value is later passed to MediaCodec and checked at decoder init.
  
  Notably decoding of 10-bit streams before this commit would "work" without
  
  returning errors but only return garbage output (on most Android devices).
  

  • [DH] libavcodec/mediacodecdec.c

• ffmpeg says "No JPEG data found in image" when reading image paths from Linux pipe

  18 septembre 2021, par user16945608

  I'm trying to convert a set of pictures into a video, and I want to read the file paths of the pictures from the pipe. The command I would like to run looks like this :

  


  find dir/*.JPG | sort | ffmpeg -f image2pipe -r 1 -vcodec mjpeg -s 6000x4000 -pix_fmt yuvj422p -i - -vcodec libx264 -s 1080x720 -r 20 -pix_fmt yuv420p out.mkv

  


  But I keep obtaining the No JPEG data found in image error. Here is the full log :

  


  Input #0, image2pipe, from 'pipe:':
  Duration: N/A, bitrate: N/A
  Stream #0:0: Video: mjpeg, yuvj422p(bt470bg/unknown/unknown), 6000x4000, 1 fps, 1 tbr, 1 tbn, 1 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (mjpeg (native) -> h264 (libx264))
[mjpeg @ 0x558e98cd7300] No JPEG data found in image
Error while decoding stream #0:0: Invalid data found when processing input
[swscaler @ 0x558e98ce9440] deprecated pixel format used, make sure you did set range correctly
[libx264 @ 0x558e98cdaac0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
[libx264 @ 0x558e98cdaac0] profile High, level 3.1, 4:2:0, 8-bit
[libx264 @ 0x558e98cdaac0] 264 - core 161 r3039 544c61f - H.264/MPEG-4 AVC codec - Copyleft
2003-2021 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=20 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, matroska, to 'out.mkv':
  Metadata:
    encoder         : Lavf58.76.100
  Stream #0:0: Video: h264 (H264 / 0x34363248), yuv420p, 1080x720, q=2-31, 20 fps, 1k tbn
    Metadata:
      encoder         : Lavc58.134.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
frame=    0 fps=0.0 q=0.0 Lsize=       1kB time=00:00:00.00 bitrate=N/A speed=   0x
video:0kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
Conversion failed!


  


  The pictures are in the following format (with mediainfo) and the filenames are in the form DSC_1234.JPG :

  


  Format                                   : JPEG
Video
Format                                   : JPEG
Width                                    : 6 000 pixels
Height                                   : 4 000 pixels
Display aspect ratio                     : 3:2
Color space                              : YUV
Chroma subsampling                       : 4:2:2
Bit depth                                : 8 bits
Compression mode                         : Lossy


  


  Also, I would like to avoid using a solution without piping the paths (with -f image2 -i DSC_%04d.JPG for example). Do you have any idea what's happening ?

  


• ffmpeg (IMAGE THUMBNAIL 1 frame) how to "choose" compression quality when we use -vframes 1 (how to do like convert -quality 60....)

  25 juillet 2021, par jini

  • PRE-CONTEXT : with ImageMagick, I'm use to do convert -quality 60 1.jpg 1.webp here "quality 60" affect the final size of the output

  


  • CONTEXT : create a poster.webp OR poster.jpg of a movie.mp4

  


  • QUESTION : how can we "achieve" the same compression level choice with ffmpeg when we want 1 frame

  


  • WHAT I TRIED [1] :

  


  ffmpeg -i movie.mp4 -vframes 1 -qmin 0 -qmax 1  0.webp

  


  and ffmpeg -i movie.mp4 -vframes 1 -qmin 50 -qmax 51 50.webp

  


  ==>> both gives the exact same size for the output.

  


  • WHAT I TRIED [2] :

  


  ffmpeg -i movie.mp4 -vframes 1 -b:v 9k bv9k.webp

  


  and ffmpeg -i movie.mp4 -vframes 1 -b:v 1k bv1k.webp

  


  ==>> both gives the exact same size for the output.

  


  what I'm I missing or miss using here ?

  


  Thanks