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• Why does ffmpeg remove SEI messages when converting FLV to h264 ?

  22 juin 2020, par Tunji_D

  I have an FLV file with h264 video tags. Each video tag that contains an h264 IDR NAL unit also also contains display orientation SEI, ie my NAL access unit for IDR key frames is [SEI, IDR].

  


  For some reason, converting this FLV file to h264 without the stream copy option strips away all the SEI messages from all IDR frames. In its place, right after the SPS and PPS NAL units, there's a single user unregistered data SEI.

  


  i.e using

  


  ffmpeg -i in.flv out.264


  


  gives [SPS, PPS, SEI, IDR, ...] where the SEI is :

  


  


  x264 - core 155 r2917 0a84d98 - H.264/MPEG-4 AVC codec - Copyleft
2003-2018 - 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=11
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=25 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

  


  


  However

  


  ffmpeg -i in.flv -c:v copy out.264


  


  preserves my SEI messages, and pretty much decodes to the raw h264 I put into the FLV muxer to generate the FLV file in the first place. Why does this happen ? Is there a flag to perform encoding but preserve SEI messages ?

  


• Not able to generate mp4 using png and mp3 audio

  6 mars 2016, par Bhaskar Dabhi

  I am totally nob to FFMPEG.
  I am trying to generate mp4 video file by merging mp3 and png image.

  When i try converting png image into mp4 it works

  ffmpeg -r 1/5.544000 -i 1.png -qscale 2 1.mp4

  But when i add mp3 audio file then it fails

  ffmpeg -r 1/5.544000 -i 1.png -i 1.mp3 -qscale 2 1.mp4

  Following is the error that i get :

  No pixel format specified, yuv444p for H.264 encoding chosen.
  
  Use -pix_fmt yuv420p for compatibility with outdated media players.
  
  
  
  [libx264 @ 0x1475be0] using SAR=1/1
  
  
  
  [libx264 @ 0x1475be0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2
  
  
  
  `[libx264 @ 0x1475be0] profile High 4:4:4 Predictive, level 3.1, 4:4:4 8-`bit
  
  
  
  [libx264 @ 0x1475be0] 264 - core 142 r2431 a5831aa - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - 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=4 threads=3 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=25 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
  
  
  
  [aac @ 0x1476660] The encoder 'aac' is experimental but experimental codecs are not enabled, add '-strict -2' if you want to use it.

  I tried using -strict -2 but still it fails.

  What wrong in the command ? How to create mp4 using mp3 and png ?

• Not able to generate mp4 using png and mp3 audio

  18 juin 2019, par Bhaskar Dabhi

  I am totally nob to FFMPEG.
  I am trying to generate mp4 video file by merging mp3 and png image.

  When i try converting png image into mp4 it works

  ffmpeg -r 1/5.544000 -i 1.png -qscale 2 1.mp4

  But when i add mp3 audio file then it fails

  ffmpeg -r 1/5.544000 -i 1.png -i 1.mp3 -qscale 2 1.mp4

  Following is the error that i get :

  No pixel format specified, yuv444p for H.264 encoding chosen.
  
  Use -pix_fmt yuv420p for compatibility with outdated media players.
  
  
  
  [libx264 @ 0x1475be0] using SAR=1/1
  
  
  
  [libx264 @ 0x1475be0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2
  
  
  
  `[libx264 @ 0x1475be0] profile High 4:4:4 Predictive, level 3.1, 4:4:4 8-`bit
  
  
  
  [libx264 @ 0x1475be0] 264 - core 142 r2431 a5831aa - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - 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=4 threads=3 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=25 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
  
  
  
  [aac @ 0x1476660] The encoder 'aac' is experimental but experimental codecs are not enabled, add '-strict -2' if you want to use it.

  I tried using -strict -2 but still it fails.

  What wrong in the command ? How to create mp4 using mp3 and png ?