[FFmpeg-user] Lossless encoding to ffv1 changes frames md5

Carl Eugen Hoyos ceffmpeg at gmail.com
Tue Dec 17 15:26:34 EET 2019


Am Di., 17. Dez. 2019 um 14:18 Uhr schrieb Alberto Mattea <alberto at mattea.info>:
>
> Hi all, I'm trying to losslessly convert some videos from grassvalley hqx to ffv1.
> Unfortunately it seems the conversion is not really lossless, as the frames md5 changes after the conversion.
> Here's what I'm doing:
>
> - Calculate md5 of the original video frames
>
> $ ffmpeg -i 01.avi -f framemd5 orig.framemd5
> ffmpeg version N-51066-ge52070e89c-static https://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2019 the FFmpeg developers
>   built with gcc 6.3.0 (Debian 6.3.0-18+deb9u1) 20170516
>   configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc-6 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gmp --enable-libgme --enable-gray --enable-libaom --enable-libfribidi --enable-libass --enable-libvmaf --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librubberband --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libvorbis --enable-libopus --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libdav1d --enable-libxvid --enable-libzvbi --enable-libzimg
>   libavutil      56. 36.101 / 56. 36.101
>   libavcodec     58. 65.100 / 58. 65.100
>   libavformat    58. 35.101 / 58. 35.101
>   libavdevice    58.  9.101 / 58.  9.101
>   libavfilter     7. 68.100 /  7. 68.100
>   libswscale      5.  6.100 /  5.  6.100
>   libswresample   3.  6.100 /  3.  6.100
>   libpostproc    55.  6.100 / 55.  6.100
> Input #0, avi, from '01.avi':
>   Duration: 00:15:04.40, start: 0.000000, bitrate: 202751 kb/s
>     Stream #0:0: Video: hqx (CHQX / 0x58514843), yuv422p16le(10 bpc, progressive), 1632x1200 [SAR 1:1 DAR 34:25], 202756 kb/s, 25 fps, 25 tbr, 25 tbn, 25 tbc
> Stream mapping:
>   Stream #0:0 -> #0:0 (hqx (native) -> rawvideo (native))
> Press [q] to stop, [?] for help
> Output #0, framemd5, to 'orig.framemd5':
>   Metadata:
>     encoder         : Lavf58.35.101
>     Stream #0:0: Video: rawvideo (Y3[10][16] / 0x100A3359), yuv422p16le(10 bpc), 1632x1200 [SAR 1:1 DAR 34:25], q=2-31, 1566720 kb/s, 25 fps, 25 tbn, 25 tbc
>     Metadata:
>       encoder         : Lavc58.65.100 rawvideo
> frame=22610 fps= 50 q=-0.0 Lsize=    1767kB time=00:15:04.40 bitrate=  16.0kbits/s speed=1.98x
> video:172966500kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
>
> - Convert
>
> $ ffmpeg -i 01.avi -c:v ffv1 01ffv1.mkv
> ffmpeg version N-51066-ge52070e89c-static https://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2019 the FFmpeg developers
>   built with gcc 6.3.0 (Debian 6.3.0-18+deb9u1) 20170516
>   configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc-6 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gmp --enable-libgme --enable-gray --enable-libaom --enable-libfribidi --enable-libass --enable-libvmaf --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librubberband --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libvorbis --enable-libopus --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libdav1d --enable-libxvid --enable-libzvbi --enable-libzimg
>   libavutil      56. 36.101 / 56. 36.101
>   libavcodec     58. 65.100 / 58. 65.100
>   libavformat    58. 35.101 / 58. 35.101
>   libavdevice    58.  9.101 / 58.  9.101
>   libavfilter     7. 68.100 /  7. 68.100
>   libswscale      5.  6.100 /  5.  6.100
>   libswresample   3.  6.100 /  3.  6.100
>   libpostproc    55.  6.100 / 55.  6.100
> Input #0, avi, from '01.avi':
>   Duration: 00:15:04.40, start: 0.000000, bitrate: 202751 kb/s
>     Stream #0:0: Video: hqx (CHQX / 0x58514843), yuv422p16le(10 bpc, progressive), 1632x1200 [SAR 1:1 DAR 34:25], 202756 kb/s, 25 fps, 25 tbr, 25 tbn, 25 tbc
> Stream mapping:
>   Stream #0:0 -> #0:0 (hqx (native) -> ffv1 (native))
> Press [q] to stop, [?] for help
> [ffv1 @ 0x6e1ce80] bits_per_raw_sample > 8, forcing range coder
> Output #0, matroska, to '01ffv1.mkv':
>   Metadata:
>     encoder         : Lavf58.35.101
>     Stream #0:0: Video: ffv1 (FFV1 / 0x31564646), yuv422p16le(10 bpc), 1632x1200 [SAR 1:1 DAR 34:25], q=2-31, 200 kb/s, 25 fps, 1k tbn, 25 tbc
>     Metadata:
>       encoder         : Lavc58.65.100 ffv1
> frame=22610 fps= 17 q=-0.0 Lsize=35631195kB time=00:15:04.36 bitrate=322759.1kbits/s speed=0.691x
> video:35630872kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000908%
>
> - Calculate md5 of the converted frames (I've stopped it after a few hundred frames, just to check the beginning)
>
> $ ffmpeg -i 01ffv1.mkv -f framemd5 converted.framemd5
> ffmpeg version N-51066-ge52070e89c-static https://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2019 the FFmpeg developers
>   built with gcc 6.3.0 (Debian 6.3.0-18+deb9u1) 20170516
>   configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc-6 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gmp --enable-libgme --enable-gray --enable-libaom --enable-libfribidi --enable-libass --enable-libvmaf --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librubberband --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libvorbis --enable-libopus --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libdav1d --enable-libxvid --enable-libzvbi --enable-libzimg
>   libavutil      56. 36.101 / 56. 36.101
>   libavcodec     58. 65.100 / 58. 65.100
>   libavformat    58. 35.101 / 58. 35.101
>   libavdevice    58.  9.101 / 58.  9.101
>   libavfilter     7. 68.100 /  7. 68.100
>   libswscale      5.  6.100 /  5.  6.100
>   libswresample   3.  6.100 /  3.  6.100
>   libpostproc    55.  6.100 / 55.  6.100
> Input #0, matroska,webm, from '01ffv1.mkv':
>   Metadata:
>     ENCODER         : Lavf58.35.101
>   Duration: 00:15:04.40, start: 0.000000, bitrate: 322745 kb/s
>     Stream #0:0: Video: ffv1 (FFV1 / 0x31564646), yuv422p10le, 1632x1200, SAR 1:1 DAR 34:25, 25 fps, 25 tbr, 1k tbn, 1k tbc (default)
>     Metadata:
>       ENCODER         : Lavc58.65.100 ffv1
>       DURATION        : 00:15:04.400000000
> Stream mapping:
>   Stream #0:0 -> #0:0 (ffv1 (native) -> rawvideo (native))
> Press [q] to stop, [?] for help
> Output #0, framemd5, to 'converted.framemd5':
>   Metadata:
>     encoder         : Lavf58.35.101
>     Stream #0:0: Video: rawvideo (Y3[10][10] / 0xA0A3359), yuv422p10le, 1632x1200 [SAR 1:1 DAR 34:25], q=2-31, 979200 kb/s, 25 fps, 25 tbn, 25 tbc (default)
>     Metadata:
>       DURATION        : 00:15:04.400000000
>       encoder         : Lavc58.65.100 rawvideo
> frame=  406 fps= 31 q=-0.0 Lsize=      32kB time=00:00:16.24 bitrate=  16.1kbits/s speed=1.23x
> video:3105900kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
>
> - Compare hashes
>
> orig.framemd5:
> #format: frame checksums
> #version: 2
> #hash: MD5
> #software: Lavf58.35.101
> #tb 0: 1/25
> #media_type 0: video
> #codec_id 0: rawvideo
> #dimensions 0: 1632x1200
> #sar 0: 1/1
> #stream#, dts,        pts, duration,     size, hash
> 0,          0,          0,        1,  7833600, 39d64300c8b749b0776423a80746d8dc
> 0,          1,          1,        1,  7833600, 12e7317d49727740187d2e23439d87d8
> 0,          2,          2,        1,  7833600, 12e7317d49727740187d2e23439d87d8
> 0,          3,          3,        1,  7833600, 0b3b0136b008ec9d67e900595be0c923
> 0,          4,          4,        1,  7833600, 97cd9b7689d1f49d1e1988a3613ffa72
> 0,          5,          5,        1,  7833600, 97cd9b7689d1f49d1e1988a3613ffa72
> 0,          6,          6,        1,  7833600, 1632e4b3ba7dc28e9dde698f3b7ec9e7
> 0,          7,          7,        1,  7833600, 796bda137d768f4ad31eb7166ea16447
> 0,          8,          8,        1,  7833600, 796bda137d768f4ad31eb7166ea16447
> 0,          9,          9,        1,  7833600, 612c13b4824bd427faa51efa7a09660d
> ...
>
> converted.framemd5:
> #format: frame checksums
> #version: 2
> #hash: MD5
> #software: Lavf58.35.101
> #tb 0: 1/25
> #media_type 0: video
> #codec_id 0: rawvideo
> #dimensions 0: 1632x1200
> #sar 0: 1/1
> #stream#, dts,        pts, duration,     size, hash
> 0,          0,          0,        1,  7833600, 3ed693fc02ba36cca92a2153afa960ac
> 0,          1,          1,        1,  7833600, 23d7482899eb8c854b26444dcdf38db4
> 0,          2,          2,        1,  7833600, 23d7482899eb8c854b26444dcdf38db4
> 0,          3,          3,        1,  7833600, 1fc392823ebc14001ee0e44c68d710e6
> 0,          4,          4,        1,  7833600, d63335f1c34132680e571549da51eac7
> 0,          5,          5,        1,  7833600, d63335f1c34132680e571549da51eac7
> 0,          6,          6,        1,  7833600, 09304bca4578458c353ecc119de0bd87
> 0,          7,          7,        1,  7833600, 0ec1e49008d1f70385dc4a1636559a30
> 0,          8,          8,        1,  7833600, 0ec1e49008d1f70385dc4a1636559a30
> 0,          9,          9,        1,  7833600, 78b22236d03517e5ceea3bd390ac2d0b
> ...
>
> Any idea of why this is happening?

The input has 10 bit precision, therefore only 10 bit are encoded.

Carl Eugen


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