[FFmpeg-user] Lossless encoding to ffv1 changes frames md5
Alberto Mattea
alberto at mattea.info
Tue Dec 17 17:04:02 EET 2019
In data martedì 17 dicembre 2019 14:53:46 CET, Paul B Mahol ha scritto:
> On 12/17/19, Alberto Mattea <alberto at mattea.info> wrote:
> > In data martedì 17 dicembre 2019 14:33:47 CET, Carl Eugen Hoyos ha scritto:
> >> 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
> >
> > Hey, thanks for the instant answer.
> > So if I understand correctly no information is being lost, it's just that
> > the 10 bits are represented over <10 bits plus 6 bits of padding> instead of
> > over <16-bits where the least significant 6 bits always happen to be zero>.
> > Is it correct?
> > I'm assuming there is padding since if I extract a raw yuv frame from the
> > hqx and the ffv1 they are both the size you would expect if they were
> > 16-bit.
>
> Thing is decoder's output should be changed so it will be 12/10 bit
> pixel format.
> Instead of using 16bit format. Assuming 4 upper bits are not having useful info.
>
Aaah I understand now. I tried forcing ffmpeg to keep all the 16 bits (by first converting to rawvideo and then encoding from that to ffv1) and now the md5 matches. I think I'm going to do this until hqx outputs in 10/12 bits format just to be sure (to be able to perform the md5 check).
As a side note, I tried using the mpdecimate filter to remove the duplicate frames (the videos are 16 -> 25fps conversions) but it changes the md5 (of corresponding frames) again, checking the source it seems it supports 8-bit only?
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