[FFmpeg-user] Lossless encoding to ffv1 changes frames md5
Carl Eugen Hoyos
ceffmpeg at gmail.com
Tue Dec 17 15:33:47 EET 2019
Am Di., 17. Dez. 2019 um 14:26 Uhr schrieb Carl Eugen Hoyos
<ceffmpeg at gmail.com>:
>
> 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.
The more difficult question is how big hqx precision really is:
The original commit specified 10 bit, but a comment in the code (same commit)
indicates 12 bit.
Carl Eugen
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