Opened 12 years ago
Closed 10 years ago
#2024 closed defect (fixed)
Reencoding dvbsub fails
Reported by: | Carl Eugen Hoyos | Owned by: | Anshul |
---|---|---|---|
Priority: | normal | Component: | avcodec |
Version: | git-master | Keywords: | dvbsub av_interleaved_write_frame |
Cc: | Anshul | Blocked By: | |
Blocking: | Reproduced by developer: | yes | |
Analyzed by developer: | yes |
Description
I tested two samples:
http://samples.ffmpeg.org/MPEG-VOB/ClosedCaptions/Starship_Troopers.vob
http://samples.ffmpeg.org/MPEG-VOB/transport/dvbsub/dvbsubtest.ts
and tried to reencode them to dvbsub. This works fine for the dvdsub sample, but fails for the dvbsub (input) sample.
$ ffmpeg -i dvbsubtest.ts -qscale 2 -mbd 2 -scodec dvbsub out.ts ffmpeg version N-47774-g26db653 Copyright (c) 2000-2012 the FFmpeg developers built on Dec 12 2012 21:57:33 with gcc 4.7 (SUSE Linux) configuration: --enable-gpl --disable-indev=jack libavutil 52. 12.100 / 52. 12.100 libavcodec 54. 79.102 / 54. 79.102 libavformat 54. 49.101 / 54. 49.101 libavdevice 54. 3.102 / 54. 3.102 libavfilter 3. 26.102 / 3. 26.102 libswscale 2. 1.103 / 2. 1.103 libswresample 0. 17.102 / 0. 17.102 libpostproc 52. 2.100 / 52. 2.100 [mpegts @ 0x2f23280] max_analyze_duration 5000000 reached at 5016000 [mpegts @ 0x2f23280] PES packet size mismatch Input #0, mpegts, from 'dvbsubtest.ts': Duration: 00:00:34.60, start: 79677.098467, bitrate: 4848 kb/s Program 1 Stream #0:0[0x1901](eng): Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p, 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc Stream #0:1[0x19a1](eng): Audio: mp2 ([4][0][0][0] / 0x0004), 48000 Hz, stereo, s16p, 256 kb/s Stream #0:2[0x19b1](eng): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006) Please use -q:a or -q:v, -qscale is ambiguous Output #0, mpegts, to 'out.ts': Metadata: encoder : Lavf54.49.101 Stream #0:0(eng): Video: mpeg2video (hq), yuv420p, 720x576 [SAR 64:45 DAR 16:9], q=2-31, 200 kb/s, 90k tbn, 25 tbc Stream #0:1(eng): Audio: mp2, 48000 Hz, stereo, s16, 128 kb/s Stream #0:2(eng): Subtitle: dvb_subtitle Stream mapping: Stream #0:0 -> #0:0 (mpeg2video -> mpeg2video) Stream #0:1 -> #0:1 (mp2 -> mp2) Stream #0:2 -> #0:2 (dvbsub -> dvbsub) Press [q] to stop, [?] for help frame= 310 fps=0.0 q=2.0 size= 0kB time=00:00:12.32 bitrate= 0.0kbits/s dup=10 drop=0Application provided invalid, non monotonically increasing dts to muxer in stream 2: 3005830 >= 1670230 av_interleaved_write_frame(): Invalid argument
Remuxing all strams fails (remuxing only audio and video works fine):
$ ffmpeg -i dvbsubtest.ts -acodec copy -vcodec copy -scodec dvbsub out.ts ffmpeg version N-47774-g26db653 Copyright (c) 2000-2012 the FFmpeg developers built on Dec 12 2012 21:57:33 with gcc 4.7 (SUSE Linux) configuration: --enable-gpl --disable-indev=jack libavutil 52. 12.100 / 52. 12.100 libavcodec 54. 79.102 / 54. 79.102 libavformat 54. 49.101 / 54. 49.101 libavdevice 54. 3.102 / 54. 3.102 libavfilter 3. 26.102 / 3. 26.102 libswscale 2. 1.103 / 2. 1.103 libswresample 0. 17.102 / 0. 17.102 libpostproc 52. 2.100 / 52. 2.100 [mpegts @ 0x1b92280] max_analyze_duration 5000000 reached at 5016000 [mpegts @ 0x1b92280] PES packet size mismatch Input #0, mpegts, from 'dvbsubtest.ts': Duration: 00:00:34.60, start: 79677.098467, bitrate: 4848 kb/s Program 1 Stream #0:0[0x1901](eng): Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p, 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc Stream #0:1[0x19a1](eng): Audio: mp2 ([4][0][0][0] / 0x0004), 48000 Hz, stereo, s16p, 256 kb/s Stream #0:2[0x19b1](eng): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006) Output #0, mpegts, to 'out.ts': Metadata: encoder : Lavf54.49.101 Stream #0:0(eng): Video: mpeg2video ([2][0][0][0] / 0x0002), yuv420p, 720x576 [SAR 64:45 DAR 16:9], q=2-31, 25 fps, 90k tbn, 25 tbc Stream #0:1(eng): Audio: mp2 ([4][0][0][0] / 0x0004), 48000 Hz, stereo, 256 kb/s Stream #0:2(eng): Subtitle: dvb_subtitle Stream mapping: Stream #0:0 -> #0:0 (copy) Stream #0:1 -> #0:1 (copy) Stream #0:2 -> #0:2 (dvbsub -> dvbsub) Press [q] to stop, [?] for help [mpegts @ 0x1b9a2e0] Application provided invalid, non monotonically increasing dts to muxer in stream 2: 3005830 >= 1670230 av_interleaved_write_frame(): Invalid argument
Remuxing only the subtitles work, but the resulting file shows no subtitles:
$ ffmpeg -i dvbsubtest.ts -qscale 2 -mbd 2 -scodec copy out.ts ffmpeg version N-47774-g26db653 Copyright (c) 2000-2012 the FFmpeg developers built on Dec 12 2012 21:57:33 with gcc 4.7 (SUSE Linux) configuration: --enable-gpl --disable-indev=jack libavutil 52. 12.100 / 52. 12.100 libavcodec 54. 79.102 / 54. 79.102 libavformat 54. 49.101 / 54. 49.101 libavdevice 54. 3.102 / 54. 3.102 libavfilter 3. 26.102 / 3. 26.102 libswscale 2. 1.103 / 2. 1.103 libswresample 0. 17.102 / 0. 17.102 libpostproc 52. 2.100 / 52. 2.100 [mpegts @ 0x2ae8280] max_analyze_duration 5000000 reached at 5016000 [mpegts @ 0x2ae8280] PES packet size mismatch Input #0, mpegts, from 'dvbsubtest.ts': Duration: 00:00:34.60, start: 79677.098467, bitrate: 4848 kb/s Program 1 Stream #0:0[0x1901](eng): Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p, 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc Stream #0:1[0x19a1](eng): Audio: mp2 ([4][0][0][0] / 0x0004), 48000 Hz, stereo, s16p, 256 kb/s Stream #0:2[0x19b1](eng): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006) Please use -q:a or -q:v, -qscale is ambiguous Output #0, mpegts, to 'out.ts': Metadata: encoder : Lavf54.49.101 Stream #0:0(eng): Video: mpeg2video (hq), yuv420p, 720x576 [SAR 64:45 DAR 16:9], q=2-31, 200 kb/s, 90k tbn, 25 tbc Stream #0:1(eng): Audio: mp2, 48000 Hz, stereo, s16, 128 kb/s Stream #0:2(eng): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006) Stream mapping: Stream #0:0 -> #0:0 (mpeg2video -> mpeg2video) Stream #0:1 -> #0:1 (mp2 -> mp2) Stream #0:2 -> #0:2 (copy) Press [q] to stop, [?] for help frame= 311 fps=0.0 q=2.0 size= 5961kB time=00:00:13.09 bitrate=3728.0kbits/s dup=10 drop=0frame= 570 fps=569 q=2.0 size= 14614kB time=00:00:23.13 bitrate=5173.9kbits/s dup=10 drop=0frame= 821 fps=546 q=2.0 size= 25327kB time=00:00:32.76 bitrate=6333.3kbits/s dup=10 drop=0PES packet size mismatch [mpeg2video @ 0x2aec140] invalid mb type in P Frame at 43 16 [mpeg2video @ 0x2aec140] Warning MVs not available [mpeg2video @ 0x2aec140] concealing 900 DC, 900 AC, 900 MV errors in P frame [mp2 @ 0x2aecc20] incomplete frame Error while decoding stream #0:1: Invalid data found when processing input frame= 866 fps=538 q=2.0 Lsize= 28381kB time=00:00:34.67 bitrate=6704.4kbits/s dup=12 drop=0 video:25613kB audio:535kB subtitle:50 global headers:0kB muxing overhead 8.332572%
Attachments (1)
Change History (16)
comment:1 by , 12 years ago
comment:2 by , 12 years ago
Still fails:
$ ffmpeg -i dvbsubtest.ts -qscale 2 -mbd 2 -scodec dvbsub out.ts ffmpeg version N-48478-g6a9af92 Copyright (c) 2000-2013 the FFmpeg developers built on Jan 5 2013 14:56:18 with gcc 4.7 (SUSE Linux) configuration: --enable-gpl --disable-indev=jack libavutil 52. 13.100 / 52. 13.100 libavcodec 54. 85.101 / 54. 85.101 libavformat 54. 59.103 / 54. 59.103 libavdevice 54. 3.102 / 54. 3.102 libavfilter 3. 32.100 / 3. 32.100 libswscale 2. 1.103 / 2. 1.103 libswresample 0. 17.102 / 0. 17.102 libpostproc 52. 2.100 / 52. 2.100 [mpegts @ 0x226e880] max_analyze_duration 5000000 reached at 5016000 [mpegts @ 0x226e880] PES packet size mismatch Input #0, mpegts, from 'dvbsubtest.ts': Duration: 00:00:34.60, start: 79677.098467, bitrate: 4848 kb/s Program 1 Stream #0:0[0x1901](eng): Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p, 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc Stream #0:1[0x19a1](eng): Audio: mp2 ([4][0][0][0] / 0x0004), 48000 Hz, stereo, s16p, 256 kb/s Stream #0:2[0x19b1](eng): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006) Please use -q:a or -q:v, -qscale is ambiguous Output #0, mpegts, to 'out.ts': Metadata: encoder : Lavf54.59.103 Stream #0:0(eng): Video: mpeg2video (hq), yuv420p, 720x576 [SAR 64:45 DAR 16:9], q=2-31, 200 kb/s, 90k tbn, 25 tbc Stream #0:1(eng): Audio: mp2, 48000 Hz, stereo, s16, 128 kb/s Stream #0:2(eng): Subtitle: dvb_subtitle Stream mapping: Stream #0:0 -> #0:0 (mpeg2video -> mpeg2video) Stream #0:1 -> #0:1 (mp2 -> mp2) Stream #0:2 -> #0:2 (dvbsub -> dvbsub) Press [q] to stop, [?] for help frame= 277 fps=0.0 q=2.0 size= 0kB time=00:00:11.00 bitrate= 0.0kbits/s dup=10 drop=0 Application provided invalid, non monotonically increasing dts to muxer in stream 2: 3005830 >= 1670230 av_interleaved_write_frame(): Invalid argument
comment:3 by , 11 years ago
Another sample with a similar issue in #2989. Probably affects any DVB sub sample.
comment:4 by , 11 years ago
I've worked out what the problem is (with the help of nevcariel, ubitux and others on #ffmpeg-devel):
- DVB subtitles are encoded as a series of rectangular bitmaps, and they are individually "flushed" to be displayed using a display segment packet.
- The way the DVB subtitles decoder (avcodec/dvbsubdec.c) currently works, is that it keeps track of all the other segments (which define regions, colour lookup tables, and contain the actual bitmaps) until a display segment is encountered, at which point it renders all these things to an AVSubtitle.
- On the encoding side, DVB subtitles differ from other subtitle codecs because it is currently the only codec that needs to have two packets to do its work: one to render the subtitle and one to indicate that it can be removed from the screen. These have (obviously) different PTS'es.
- It's possible that a later AVSubtitle appears before an earlier one dissappears from the screen. In fact, it's quite common for live subtitling, where each word is pushed & displayed as a separate region (have a look at http://samples.ffmpeg.org/MPEG-VOB/transport/dvbsub/dvbsubtest.ts for an example of this happening).
- Because the current subtitle encoding happens to write out the display & clear packets for DVB in sequence, a later subtitle can trigger the above error in the muxer.
So this is the problem. As for the solution: I don't have a clue on how to fix this cleanly. There's already quite a bit of DVB subtitles specific code in ffmpeg.c, and I'd rather remove from it than add to it, fixing the issue in the decoder.
I'd love to get this fixed, so I'm hoping that someone has an idea how this could be solved.
comment:5 by , 11 years ago
Hi,
I modified ffmpeg to queue the clear packet of DVB subtitles instead of writing it out. I'm not sure if this is acceptable, and I'm pretty sure the code is not upto the required standards.
I'd like some feedback on wether this is an acceptable solution or what I have to do to get this merged.
by , 11 years ago
Attachment: | ffmpeg_dvbsubs_queue_clear.patch added |
---|
A patch that adds queueing to OutputStream to sidestep this bug.
follow-up: 7 comment:6 by , 11 years ago
Please send patches to the ffmpeg-devel mailing list where they get more attention.
comment:7 by , 11 years ago
Replying to cehoyos:
Please send patches to the ffmpeg-devel mailing list where they get more attention.
I have, I just used the wrong email, so it's awaiting moderation.
comment:8 by , 11 years ago
Can I add something in so people will understand how DVBSUBS work.
Dvb subs works on an idea of regions and objects, there are NO CLEAR SUBS commands, what is sent is a new region list with 0 regions, there should be no code to explicitly send clear screen or anything like this.
What will happen is this
New region with 2 objects
New region with 1 object
New region with 0 objects
New region with 1 object
Now all these new regions have a "timeout" which says that if NO NEW DATA arrives then clear the screen as sonething has gone wrong, stream corrupted, out of sync etc.
The current ffmpeg fails in this as it does as posted above and tries to create a "clear screen" packet when it SHOULD NOT.
What should happen is that once encoding it should check the timeout perion and if expired send a "New region with 0 objects", this means we can remove the hack in ffmpeg which makes up 2 packets when it should not.
comment:9 by , 11 years ago
"Remuxing only the subtitles work, but the resulting file shows no subtitles" - this issue from head should be fixed with https://github.com/FFmpeg/FFmpeg/commit/c917cde9cc52ad1ca89926a617f847bc9861d5a0 commit.
comment:10 by , 11 years ago
Remuxing the dvb subtitles was fixed by Serhii Marchuk in c917cde9
The problems with transcoding dvb subtitles are still reproducible.
comment:11 by , 10 years ago
Owner: | set to |
---|---|
Status: | new → open |
comment:12 by , 10 years ago
Analyzed by developer: | set |
---|---|
Component: | undetermined → avcodec |
Reproduced by developer: | set |
comment:13 by , 10 years ago
Problem is due to setting end_display_time using page_time_out in dvbsub decoder, where spec specify decoder should not rely only on page_time_out.
comment:14 by , 10 years ago
Cc: | added |
---|
For the dvbdub → dvbsub case, the input sample is strange, at it has two consecutive subtitles packets with data in them. Normally, dvbsub comes with a packet of data, then an empty packet to clear it.
ffmpeg is still not completely prepared to work with the various kind of subtitles packets, and it is a tricky API design question.