[FFmpeg-user] Size of 10-bit 4:2:2 video streams?
Hi all, I have a 10-bit 4:2:2 (yuv422p10le) AVI file containing only a video stream: Input #0, avi, from 'test.avi': Duration: 01:28:00.80, start: 0.00, bitrate: 221185 kb/s Stream #0:0: Video: v210 (v210 / 0x30313276), yuv422p10le, 720x576, 25 fps, 25 tbr, 25 tbn, 25 tbc The file has a size of 146 GB = 146004770816 bytes. Am I correct to infer that those 10-bit YUV values are grouped into 30-bit packets and encoded into 32-bit/4-byte packets? With 20 bits per pixel (Y + either U or V), that would give a theoretical file size of: 88 * 60 * 25 * 720 * 576 * (10 + 10) / 30 * 32 / 8 = 14598144 bytes Which seems to more or less match the original file size. Now here's my problem. When I extract the raw video stream: ffmpeg -i test.avi -c:v rawvideo -pix_fmt yuv422p10le -f rawvideo test.raw I get a RAW video file with a size of 96 GB = 96636395520 bytes. I’ve lost one third of the video stream. Another strange thing: if I copy the video stream to another AVI file: ffmpeg -i test.avi -c copy test.copy.avi The resulting file has a size of 64 GB = 64425220302 bytes. This time I’ve lost 56% of the video stream. What's happening here? It seems like I’m missing something obvious. Thanks for any help, Olivier ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Size of 10-bit 4:2:2 video streams?
On 9/15/22, Bruchez Olivier via ffmpeg-user wrote: > Hi all, > > I have a 10-bit 4:2:2 (yuv422p10le) AVI file containing only a video > stream: > > Input #0, avi, from 'test.avi': > Duration: 01:28:00.80, start: 0.00, bitrate: 221185 kb/s > Stream #0:0: Video: v210 (v210 / 0x30313276), yuv422p10le, 720x576, 25 > fps, 25 tbr, 25 tbn, 25 tbc > > The file has a size of 146 GB = 146004770816 bytes. > > Am I correct to infer that those 10-bit YUV values are grouped into 30-bit > packets and encoded into 32-bit/4-byte packets? > > With 20 bits per pixel (Y + either U or V), that would give a theoretical > file size of: > > 88 * 60 * 25 * 720 * 576 * (10 + 10) / 30 * 32 / 8 = 14598144 bytes > > Which seems to more or less match the original file size. > > Now here's my problem. When I extract the raw video stream: > > ffmpeg -i test.avi -c:v rawvideo -pix_fmt yuv422p10le -f rawvideo test.raw > > I get a RAW video file with a size of 96 GB = 96636395520 bytes. I’ve lost > one third of the video stream. > > Another strange thing: if I copy the video stream to another AVI file: > > ffmpeg -i test.avi -c copy test.copy.avi > > The resulting file has a size of 64 GB = 64425220302 bytes. This time I’ve > lost 56% of the video stream. > > What's happening here? It seems like I’m missing something obvious. > Can not guess without access to the file in question. > Thanks for any help, > Olivier > ___ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Size of 10-bit 4:2:2 video streams?
On 15.09.22, 14:15, "one...@gmail.com" wrote: > > The file has a size of 146 GB = 146004770816 bytes. > > Can not guess without access to the file in question. I understand, but the file is quite large (146 GB), so it's a bit difficult to share. :( Olivier ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Size of 10-bit 4:2:2 video streams?
On 9/15/2022 5:15 AM, Paul B Mahol wrote: Can not guess without access to the file in question. Of course one can guess without the file. Making guesses is part of scientific discovery- make a guess then see if it's correct; if it's not, understand why and make another. Either way, people can learn from it. Even an AVI file has some amount of packaging around the data, so when you remove that to a raw video file, the data is discarded. Should 1/3 of the file be formatting? Can't answer that myself, but it sounds high. Is there an audio stream in the original file? The original email says no but verify that anyway. Going from AVI to AVI? Since the console output from that wasn't included my -guess- is that the content was repackaged into the new container and something of the original causes the huge increase in size. Always include the complete output of ffmpeg commands when asking questions, also use the latest ffmpeg available. z! ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Size of 10-bit 4:2:2 video streams?
On Thu, 15 Sept 2022 at 13:50, Bruchez Olivier via ffmpeg-user wrote: > I understand, but the file is quite large (146 GB), so it's a bit difficult > to share. :( Side question: can an incomplete AVI be played? If yes/'it depends', perhaps a portion of OP's file might be illuminating? Cheers, Rob ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Size of 10-bit 4:2:2 video streams?
I‘d rather like to start by asking the much simpler question whether the processed files can be played back at all, and if so, are they visually identical and are all other parameters identical to the source file, or are they different in any way? If they are visually identical, are there any measurable differences? Erik ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Size of 10-bit 4:2:2 video streams?
Hi all, So I made some further tests and discovered that my original AVI file is simply corrupted. It's supposed to have 88 minutes of video, but it fails after 38 minutes. That's why all the files I generated were smaller than expected. I didn't notice this for the simple reason that ffmpeg "fails" (?) silently after 38 minutes. It doesn't output any error message. It just stops after 38 minutes. Example for an AVI-to-AVI copy: ... frame=57978 fps=154 q=-1.0 size=62615951kB time=00:38:39.12 bitrate=221183.0kbits/s speed=6.14x frame=58011 fps=153 q=-1.0 size=62651535kB time=00:38:40.44 bitrate=221182.8kbits/s speed=6.14x frame=58047 fps=153 q=-1.0 size=62690447kB time=00:38:41.88 bitrate=221182.9kbits/s speed=6.13x frame=58083 fps=153 q=-1.0 size=62729359kB time=00:38:43.32 bitrate=221183.0kbits/s speed=6.13x frame=58119 fps=153 q=-1.0 size=62768271kB time=00:38:44.76 bitrate=221183.1kbits/s speed=6.12x frame=58133 fps=153 q=-1.0 size=62783375kB time=00:38:45.32 bitrate=221183.1kbits/s speed=6.12x frame=58172 fps=153 q=-1.0 size=62825359kB time=00:38:46.88 bitrate=221182.6kbits/s speed=6.11x frame=58211 fps=153 q=-1.0 size=62867599kB time=00:38:48.44 bitrate=221183.0kbits/s speed= 6.1x frame=58254 fps=152 q=-1.0 Lsize=62915254kB time=00:38:50.12 bitrate=221191.1kbits/s speed=6.08x video:62914320kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.001485% I guess I will have to check the file on our LTO tapes... Does anybody have any suggestion about how I could retrieve the video stream after 38 minutes? Knowing that it's supposed to be "uncompressed" video (i.e. v210 / yuv422p10l)? Thanks in advance, Olivier On 9/15/22, Bruchez Olivier via ffmpeg-user wrote: > Hi all, > > I have a 10-bit 4:2:2 (yuv422p10le) AVI file containing only a video > stream: > > Input #0, avi, from 'test.avi': > Duration: 01:28:00.80, start: 0.00, bitrate: 221185 kb/s > Stream #0:0: Video: v210 (v210 / 0x30313276), yuv422p10le, 720x576, 25 > fps, 25 tbr, 25 tbn, 25 tbc > > The file has a size of 146 GB = 146004770816 bytes. > > Am I correct to infer that those 10-bit YUV values are grouped into 30-bit > packets and encoded into 32-bit/4-byte packets? > > With 20 bits per pixel (Y + either U or V), that would give a theoretical > file size of: > > 88 * 60 * 25 * 720 * 576 * (10 + 10) / 30 * 32 / 8 = 14598144 bytes > > Which seems to more or less match the original file size. > > Now here's my problem. When I extract the raw video stream: > > ffmpeg -i test.avi -c:v rawvideo -pix_fmt yuv422p10le -f rawvideo test.raw > > I get a RAW video file with a size of 96 GB = 96636395520 bytes. I’ve lost > one third of the video stream. > > Another strange thing: if I copy the video stream to another AVI file: > > ffmpeg -i test.avi -c copy test.copy.avi > > The resulting file has a size of 64 GB = 64425220302 bytes. This time I’ve > lost 56% of the video stream. > > What's happening here? It seems like I’m missing something obvious. > > Thanks for any help, > Olivier ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Size of 10-bit 4:2:2 video streams?
Hello, On 9/20/2022 6:11 AM, Bruchez Olivier via ffmpeg-user wrote: So I made some further tests and discovered that my original AVI file is simply corrupted. It's supposed to have 88 minutes of video, but it fails after 38 minutes. What does "fails" mean? The player stops? Which player? The video goes black but playing continues? Please be specific. I didn't notice this for the simple reason that ffmpeg "fails" (?) silently after 38 minutes. It doesn't output any error message. It just stops after 38 minutes. Example for an AVI-to-AVI copy: ... frame=57978 fps=154 q=-1.0 size=62615951kB time=00:38:39.12 bitrate=221183.0kbits/s speed=6.14x frame=58011 fps=153 q=-1.0 size=62651535kB time=00:38:40.44 bitrate=221182.8kbits/s speed=6.14x frame=58047 fps=153 q=-1.0 size=62690447kB time=00:38:41.88 bitrate=221182.9kbits/s a) as long as the status messages continue, it doesn't look like anything has stopped. b) the complete command line is missing, so we don't know what's actually being done. You may want to try multiple players to see what's in the file and look at it with ffprobe and mediainfo. Also try encoding into a different format which will force ffmpeg to demux/decode the frames; that might turn up something. As per the list FAQ, always include the complete command line and DO NOT top-post. z! ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Size of 10-bit 4:2:2 video streams?
Hi Marc, Thanks for your answer. /So I made some further tests and discovered that my original AVI file is />/simply corrupted. It's supposed to have 88 minutes of video, but it fails />/after 38 minutes. / What does "fails" mean? The player stops? Which player? The video goes black but playing continues? Please be specific. ffmpeg (a very recent version - or any version) will stop copying the stream after 00:38:50.12 (instead of 01:28:00.80): ffmpeg -i test.avi -c copy test.copy.avi ffmpeg version N-63101-gc92edd969a-static https://johnvansickle.com/ffmpeg/ Copyright (c) 2000-2022 the FFmpeg developers built with gcc 8 (Debian 8.3.0-6) configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc --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 57. 36.101 / 57. 36.101 libavcodec 59. 42.104 / 59. 42.104 libavformat 59. 30.101 / 59. 30.101 libavdevice 59. 8.101 / 59. 8.101 libavfilter 8. 48.100 / 8. 48.100 libswscale 6. 8.108 / 6. 8.108 libswresample 4. 9.100 / 4. 9.100 libpostproc 56. 7.100 / 56. 7.100 [avi @ 0x653e900] non-interleaved AVI Input #0, avi, from 'test.avi': Duration: 01:28:00.80, start: 0.00, bitrate: 221185 kb/s Stream #0:0: Video: v210 (v210 / 0x30313276), yuv422p10le, 720x576, 25 fps, 25 tbr, 25 tbn Output #0, avi, to 'test.copy.avi': Metadata: ISFT : Lavf59.30.101 Stream #0:0: Video: v210 (v210 / 0x30313276), yuv422p10le, 720x576, q=2-31, 25 fps, 25 tbr, 25 tbn Stream mapping: Stream #0:0 -> #0:0 (copy) Press [q] to stop, [?] for help frame=58254 fps=128 q=-1.0 Lsize=62915254kB time=00:38:50.12 bitrate=221191.1kbits/s speed=5.12x video:62914320kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.001485% The exit code is zero: echo $? 0 test.avi is still the 146-GB file I mentioned originally. You may want to try multiple players to see what's in the file and look at it with ffprobe and mediainfo. Also try encoding into a different format which will force ffmpeg to demux/decode the frames; that might turn up something. Here are a few things I've tried: - I've checked other AVI files in our archive coming from the same company. They "behave" as expected, i.e. they indeed contain about 1.5 GB per minute of video stream (SD video) and can be copied or transcoded from beginning to end. No problem there. I've only found one single problematic file. - Play the problematic file with VLC. It stops the playback after 38 minutes as well and doesn't even display the full duration of the file (01:28:00). - Examine it with mediainfo (full log here https://drive.google.com/drive/folders/1h2GxriHtvx86jxcpN41GKmJBURGO3y6P?usp=sharing). mediainfo says the duration is 01:28:00.800, but the "source duration" is 00:00:38.840 (not 38 minutes, but 38 seconds, which is weird!). - Transcode the AVI to MKV/H.264 (full command line available, but pretty standard). The resulting MKV file has a duration of 38 minutes only and can be played without any problem. Actually, I think I can do pretty much anything with the problematic AVI file using ffmpeg. It will just see it as a normal 38-minute file. - Examine the file with ffprobe (ffprobe -hide_banner -select_streams v:0 -show_frames). The full output log is available at the same location as the mediainfo output. I get information for 58254 frames, so about 38 minutes of video. Thanks, Olivier ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Size of 10-bit 4:2:2 video streams?
On 9/21/22, Olivier Bruchez via ffmpeg-user wrote: > Hi Marc, > > Thanks for your answer. > >>> /So I made some further tests and discovered that my original AVI >>> file is />/simply corrupted. It's supposed to have 88 minutes of >>> video, but it fails />/after 38 minutes. / >> What does "fails" mean? The player stops? Which player? The video goes >> black >> but playing continues? Please be specific. > > ffmpeg (a very recent version - or any version) will stop copying the > stream after 00:38:50.12 (instead of 01:28:00.80): > > ffmpeg -i test.avi -c copy test.copy.avi > ffmpeg version N-63101-gc92edd969a-static > https://johnvansickle.com/ffmpeg/ Copyright (c) 2000-2022 the FFmpeg > developers >built with gcc 8 (Debian 8.3.0-6) >configuration: --enable-gpl --enable-version3 --enable-static > --disable-debug --disable-ffplay --disable-indev=sndio > --disable-outdev=sndio --cc=gcc --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 57. 36.101 / 57. 36.101 >libavcodec 59. 42.104 / 59. 42.104 >libavformat59. 30.101 / 59. 30.101 >libavdevice59. 8.101 / 59. 8.101 >libavfilter 8. 48.100 / 8. 48.100 >libswscale 6. 8.108 / 6. 8.108 >libswresample 4. 9.100 / 4. 9.100 >libpostproc56. 7.100 / 56. 7.100 > [avi @ 0x653e900] non-interleaved AVI This 'non-interleaved AVI' can be problematic. Does other files report similar? > Input #0, avi, from 'test.avi': >Duration: 01:28:00.80, start: 0.00, bitrate: 221185 kb/s >Stream #0:0: Video: v210 (v210 / 0x30313276), yuv422p10le, 720x576, > 25 fps, 25 tbr, 25 tbn > Output #0, avi, to 'test.copy.avi': >Metadata: > ISFT: Lavf59.30.101 >Stream #0:0: Video: v210 (v210 / 0x30313276), yuv422p10le, 720x576, > q=2-31, 25 fps, 25 tbr, 25 tbn > Stream mapping: >Stream #0:0 -> #0:0 (copy) > Press [q] to stop, [?] for help > frame=58254 fps=128 q=-1.0 Lsize=62915254kB time=00:38:50.12 > bitrate=221191.1kbits/s speed=5.12x > video:62914320kB audio:0kB subtitle:0kB other streams:0kB global > headers:0kB muxing overhead: 0.001485% > > The exit code is zero: > > echo $? > 0 > > test.avi is still the 146-GB file I mentioned originally. > >> You may want to try multiple players to see what's in the file and >> look at >> it with ffprobe and mediainfo. Also try encoding into a different format >> which will force ffmpeg to demux/decode the frames; that might turn up >> something. > > Here are a few things I've tried: > > - I've checked other AVI files in our archive coming from the same > company. They "behave" as expected, i.e. they indeed contain about 1.5 > GB per minute of video stream (SD video) and can be copied or transcoded > from beginning to end. No problem there. I've only found one single > problematic file. > > - Play the problematic file with VLC. It stops the playback after 38 > minutes as well and doesn't even display the full duration of the file > (01:28:00). > > - Examine it with mediainfo (full log here > https://drive.google.com/drive/folders/1h2GxriHtvx86jxcpN41GKmJBURGO3y6P?usp=sharing). > mediainfo says the duration is 01:28:00.800, but the "source duration" > is 00:00:38.840 (not 38 minutes, but 38 seconds, which is weird!). > > - Transcode the AVI to MKV/H.264 (full command line available, but > pretty standard). The resulting MKV file has a duration of 38 minutes > only and can be played without any problem. Actually, I think I can do > pretty much anything with the problematic AVI file using ffmpeg. It will > just see it as a normal 38-minute file. > > - Examine the file with ffprobe (ffprobe -hide_banner -select_streams > v:0 -show_frames). The full output log is available at the same location > as the mediainfo output. I get information for 58254 frames, so about 38 > minutes of video. It could be that index for frames in AVI is not listing all entries. Hard to guess. You could inspect file in some AVI file format analyzer. If there is such thing available. There could be still bug in avi demuxer but without file its very limited to find out such bug. > > Thanks, > > Olivier > > ___ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > __
Re: [FFmpeg-user] Size of 10-bit 4:2:2 video streams?
The only occurrence of "non-interleaved AVI" is on avidec.c: if (avi->non_interleaved) { av_log(s, AV_LOG_INFO, "non-interleaved AVI\n"); clean_index(s); } and from a quick read of clean_index(), all that's doing is building a new index for a given stream. Absent other info, I'm not sure the message is more than information. On 9/21/2022 12:59 AM, Paul B Mahol wrote: It could be that index for frames in AVI is not listing all entries. Hard to guess. You could inspect file in some AVI file format analyzer. If there is such thing available. In theory, avicodec will do it but it's quite old, same for vitrualdubmod and gspot (http://www.headbands.com/gspot/), but then AVI format is also quite old. I have used gspot before and it was useful, haven't tried it for this purpose. https://greshka.net/avicheck/ has some interesting suggestions, which eventually land on "ffmpeg -v 5 -i FILE.avi -f null -" (decode to null output, turn up the error reporting. I'll echo Paul's thoughts that the AVI is somewhat corrupt, at least the metadata is badly wrong. It's possible that by either poking the metadata to "correctness" or ignoring a lot of errors, usable video could be pulled out. Later, z! ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Size of 10-bit 4:2:2 video streams?
On 21.09.22 19:06, Carl Zwanzig wrote: On 9/21/2022 12:59 AM, Paul B Mahol wrote: It could be that index for frames in AVI is not listing all entries. Hard to guess. You could inspect file in some AVI file format analyzer. If there is such thing available. In theory, avicodec will do it but it's quite old, same for vitrualdubmod and gspot (http://www.headbands.com/gspot/), but then AVI format is also quite old. I have used gspot before and it was useful, haven't tried it for this purpose. https://greshka.net/avicheck/ has some interesting suggestions, which eventually land on "ffmpeg -v 5 -i FILE.avi -f null -" (decode to null output, turn up the error reporting. I'll echo Paul's thoughts that the AVI is somewhat corrupt, at least the metadata is badly wrong. It's possible that by either poking the metadata to "correctness" or ignoring a lot of errors, usable video could be pulled out. Thanks Marc, Paul, and onemda! I haven't had the time to do it, but I'll try those old tools. It they don't work, I'll even try to write some code to extract the missing frames. There must be a way to read them back! Best, Olivier ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Size of 10-bit 4:2:2 video streams?
On 03/10/2022 09:40, Olivier Bruchez via ffmpeg-user wrote: On 21.09.22 19:06, Carl Zwanzig wrote: On 9/21/2022 12:59 AM, Paul B Mahol wrote: It could be that index for frames in AVI is not listing all entries. Hard to guess. You could inspect file in some AVI file format analyzer. If there is such thing available. In theory, avicodec will do it but it's quite old, same for vitrualdubmod and gspot (http://www.headbands.com/gspot/), but then AVI format is also quite old. I have used gspot before and it was useful, haven't tried it for this purpose. https://greshka.net/avicheck/ has some interesting suggestions, which eventually land on "ffmpeg -v 5 -i FILE.avi -f null -" (decode to null output, turn up the error reporting. I'll echo Paul's thoughts that the AVI is somewhat corrupt, at least the metadata is badly wrong. It's possible that by either poking the metadata to "correctness" or ignoring a lot of errors, usable video could be pulled out. Thanks Marc, Paul, and onemda! I haven't had the time to do it, but I'll try those old tools. It they don't work, I'll even try to write some code to extract the missing frames. There must be a way to read them back! If you know a bit about the AVI chunk structure, MediaTrace (which basically is another output mode built into MediaInfo) could be an option to debug your file: https://mediaarea.net/MediaTrace Finally, depending on the amount of time you are willing to invest, using a basic hex editor software for looking at the raw AVI file is always a possibility once you have a rough idea at which file position things are going wrong. Reading the binary RIFF chunk structure isn't too hard if you know ASCII and hexadecimal numbers :) Regards, Tobias ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".