[FFmpeg-trac] #9719(undetermined:new): FFmpeg HLS output with subtitles results in segmentation fault starting from 5.x
FFmpeg
trac at avcodec.org
Tue Apr 26 11:17:43 EEST 2022
#9719: FFmpeg HLS output with subtitles results in segmentation fault starting
from 5.x
-------------------------------------+-------------------------------------
Reporter: wout | Owner: (none)
Type: defect | Status: new
Priority: normal | Component:
| undetermined
Version: git-master | Resolution:
Keywords: | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Changes (by wout):
* version: unspecified => git-master
Old description:
> I am trying to create a HLS output for multiple video, audio and
> subtitles. I map the lowest video stream (0:v:2) multiple times to allow
> using it in the `var_stream_map` for subtitle only entries. This is
> needed because I cannot specify an entry without a video (for example
> "s:0,name:en,sgroup:subtitle,language:en,default:NO" is not allowed)
>
> {{{
> ffmpeg -re -fflags +genpts -i /path/to/multilang.mp4 -i /path/to/en.vtt
> -i /path/to/it.vtt -i /path/to/de.vtt -i /path/to/ru.vtt -i
> /path/to/fa.vtt -i /path/to/da.vtt -i /path/to/es.vtt -i /path/to/hr.vtt
> -c:a copy -c:v copy -c:s webvtt -map 1:s:0 -map 2:s:0 -map 3:s:0 -map
> 4:s:0 -map 5:s:0 -map 6:s:0 -map 7:s:0 -map 8:s:0 -map 0:v:2 -map 0:v:2
> -map 0:v:2 -map 0:v:2 -map 0:v:2 -map 0:v:2 -map 0:v:2 -map 0:v:2 -map
> 0:a:0 -map 0:a:1 -map 0:a:2 -map 0:a:3 -map 0:a:4 -map 0:a:5 -map 0:a:6
> -map 0:v:0 -map 0:v:1 -map 0:v:2 -map 0:v:3 -map 0:v:4
> -max_interleave_delta 10000000 -muxdelay 0 -f hls -var_stream_map
> "a:0,name:en_audio,agroup:audio,language:en,default:YES
> a:1,name:it_audio,agroup:audio,language:it,default:NO
> a:2,name:ru_audio,agroup:audio,language:ru,default:NO
> a:3,name:ar_audio,agroup:audio,language:ar,default:NO
> a:4,name:da_audio,agroup:audio,language:da,default:NO
> a:5,name:sw_audio,agroup:audio,language:sw,default:NO
> a:6,name:zh_audio,agroup:audio,language:zh,default:NO
> v:0,name:en,s:0,sgroup:subtitle,language:en,default:NO
> v:1,name:it,s:1,sgroup:subtitle,language:it,default:NO
> v:2,name:de,s:2,sgroup:subtitle,language:de,default:NO
> v:3,name:ru,s:3,sgroup:subtitle,language:ru,default:NO
> v:4,name:fa,s:4,sgroup:subtitle,language:fa,default:NO
> v:5,name:da,s:5,sgroup:subtitle,language:da,default:NO
> v:6,name:es,s:6,sgroup:subtitle,language:es,default:NO
> v:7,name:hr,s:7,sgroup:subtitle,language:hr,default:NO
> v:8,name:1080p,agroup:audio v:9,name:720p,agroup:audio
> v:10,name:480p,agroup:audio v:11,name:360p,agroup:audio
> v:12,name:240p,agroup:audio" -master_pl_name master.m3u8
> -hls_delete_threshold 4 -hls_segment_filename "/path/to/hls/%v_%d.ts"
> -hls_start_number_source datetime -hls_time 10 -hls_init_time 10
> -hls_list_size 6 -hls_flags
> delete_segments+independent_segments+round_durations
> "/path/to/hls/%v.m3u8"
> }}}
>
> This worked perfectly in previous FFmpeg versions, but starting from
> 5.0.0 this results in a segmentation fault:
>
> {{{
> Program terminated with signal SIGSEGV, Segmentation fault.
> #0 0x000056073c3a6edd in ff_write_chained (dst=0x56073f3eda40,
> dst_stream=-1, pkt=0x56073ea5d4c0, src=<optimized out>, interleave=0) at
> libavformat/mux.c:1310
> }}}
>
> I think it is caused by the following commit:
> https://github.com/FFmpeg/FFmpeg/commit/2f710734c878b95eaeb9b84b0b5f367ab976c1bd
>
> Without the whole subtitles part, the command runs without an issue.
New description:
I am trying to create a HLS output for multiple video, audio and
subtitles. I map the lowest video stream (0:v:2) multiple times to allow
using it in the `var_stream_map` for subtitle only entries. This is needed
because I cannot specify an entry without a video (for example
"s:0,name:en,sgroup:subtitle,language:en,default:NO" is not allowed)
{{{
ffmpeg -re -fflags +genpts -i /path/to/multilang.mp4 -i /path/to/en.vtt -i
/path/to/it.vtt -i /path/to/de.vtt -i /path/to/ru.vtt -i /path/to/fa.vtt
-i /path/to/da.vtt -i /path/to/es.vtt -i /path/to/hr.vtt -c:a copy -c:v
copy -c:s webvtt -map 1:s:0 -map 2:s:0 -map 3:s:0 -map 4:s:0 -map 5:s:0
-map 6:s:0 -map 7:s:0 -map 8:s:0 -map 0:v:2 -map 0:v:2 -map 0:v:2 -map
0:v:2 -map 0:v:2 -map 0:v:2 -map 0:v:2 -map 0:v:2 -map 0:a:0 -map 0:a:1
-map 0:a:2 -map 0:a:3 -map 0:a:4 -map 0:a:5 -map 0:a:6 -map 0:v:0 -map
0:v:1 -map 0:v:2 -map 0:v:3 -map 0:v:4 -max_interleave_delta 10000000
-muxdelay 0 -f hls -var_stream_map
"a:0,name:en_audio,agroup:audio,language:en,default:YES
a:1,name:it_audio,agroup:audio,language:it,default:NO
a:2,name:ru_audio,agroup:audio,language:ru,default:NO
a:3,name:ar_audio,agroup:audio,language:ar,default:NO
a:4,name:da_audio,agroup:audio,language:da,default:NO
a:5,name:sw_audio,agroup:audio,language:sw,default:NO
a:6,name:zh_audio,agroup:audio,language:zh,default:NO
v:0,name:en,s:0,sgroup:subtitle,language:en,default:NO
v:1,name:it,s:1,sgroup:subtitle,language:it,default:NO
v:2,name:de,s:2,sgroup:subtitle,language:de,default:NO
v:3,name:ru,s:3,sgroup:subtitle,language:ru,default:NO
v:4,name:fa,s:4,sgroup:subtitle,language:fa,default:NO
v:5,name:da,s:5,sgroup:subtitle,language:da,default:NO
v:6,name:es,s:6,sgroup:subtitle,language:es,default:NO
v:7,name:hr,s:7,sgroup:subtitle,language:hr,default:NO
v:8,name:1080p,agroup:audio v:9,name:720p,agroup:audio
v:10,name:480p,agroup:audio v:11,name:360p,agroup:audio
v:12,name:240p,agroup:audio" -master_pl_name master.m3u8
-hls_delete_threshold 4 -hls_segment_filename "/path/to/hls/%v_%d.ts"
-hls_start_number_source datetime -hls_time 10 -hls_init_time 10
-hls_list_size 6 -hls_flags
delete_segments+independent_segments+round_durations
"/path/to/hls/%v.m3u8"
}}}
This worked perfectly in previous FFmpeg versions, but starting from 5.x
this results in a segmentation fault:
{{{
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x000056073c3a6edd in ff_write_chained (dst=0x56073f3eda40,
dst_stream=-1, pkt=0x56073ea5d4c0, src=<optimized out>, interleave=0) at
libavformat/mux.c:1310
}}}
{{{
(gdb) backtrace
#0 0x000055ec0a65f9ed in ff_write_chained (dst=0x55ec0d193800,
dst_stream=-8, pkt=0x55ec0ceda380, src=<optimized out>, interleave=0) at
libavformat/mux.c:1363
#1 0x000055ec0a5e87fb in hls_write_packet (s=<optimized out>,
pkt=0x55ec0ceda380) at libavformat/hlsenc.c:2669
#2 0x000055ec0a65c864 in write_packet (s=s at entry=0x55ec0d1a3900,
pkt=pkt at entry=0x55ec0ceda380) at libavformat/mux.c:771
#3 0x000055ec0a65cd7b in interleaved_write_packet (has_packet=0,
flush=<optimized out>, pkt=<optimized out>, s=<optimized out>) at
libavformat/mux.c:1145
#4 write_packet_common (s=s at entry=0x55ec0d1a3900, st=<optimized out>,
pkt=pkt at entry=0x55ec0ceda380, interleaved=interleaved at entry=1) at
libavformat/mux.c:1170
#5 0x000055ec0a65df5b in write_packets_common (s=s at entry=0x55ec0d1a3900,
pkt=pkt at entry=0x55ec0ceda380, interleaved=interleaved at entry=1) at
libavformat/mux.c:1230
#6 0x000055ec0a65f65a in write_packets_common (interleaved=1,
pkt=0x55ec0ceda380, s=0x55ec0d1a3900) at libavformat/mux.c:1214
#7 av_interleaved_write_frame (s=s at entry=0x55ec0d1a3900,
pkt=pkt at entry=0x55ec0ceda380) at libavformat/mux.c:1286
#8 0x000055ec0a2b53f0 in of_write_packet (of=<optimized out>,
pkt=0x55ec0ceda380, ost=0x55ec0ced9940, unqueue=<optimized out>) at
fftools/ffmpeg_mux.c:181
#9 0x000055ec0a2d4e88 in do_streamcopy (pkt=<optimized out>,
ost=<optimized out>, ist=<optimized out>) at fftools/ffmpeg.c:1938
#10 process_input_packet (ist=<optimized out>, pkt=<optimized out>,
no_eof=<optimized out>) at fftools/ffmpeg.c:2601
#11 0x000055ec0a2d7666 in process_input (file_index=<optimized out>) at
fftools/ffmpeg.c:4225
#12 transcode_step () at fftools/ffmpeg.c:4365
#13 transcode () at fftools/ffmpeg.c:4419
#14 0x000055ec0a2b0cbe in main (argc=109, argv=0x7ffd7456d108) at
fftools/ffmpeg.c:4625
}}}
It is caused by commit c64d56a2f53455f803456811873ff08fce98e122 as
reverting it resolves the issue.
--
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Ticket URL: <https://trac.ffmpeg.org/ticket/9719#comment:1>
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