[FFmpeg-trac] #6776(undetermined:new): hls muxer does not include the first segment in m3u8 files when segmenting to fmp4
FFmpeg
trac at avcodec.org
Tue Oct 24 20:26:24 EEST 2017
#6776: hls muxer does not include the first segment in m3u8 files when segmenting
to fmp4
-------------------------------------+-------------------------------------
Reporter: pickles | Type: defect
Status: new | Priority: normal
Component: | Version:
undetermined | unspecified
Keywords: | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
The hls muxer does not include the first segment in the m3u8 file when
`hls_segment_type` is set to output fmp4 segments, so playback only begins
from the second segment onwards. Setting `-hls_list_size 0` does not help.
How to reproduce:
{{{
ffmpeg -i input.mp4 -hls_segment_filename '%d.m4s' -hls_segment_type fmp4
-f hls fmp4.m3u8
ffmpeg version N-88116-gacf7063 Copyright (c) 2000-2017 the FFmpeg
developers
built with gcc 4.9.2 (Debian 4.9.2-10)
configuration: --prefix=/usr --enable-avfilter --enable-shared --enable-
avresample --enable-gpl --enable-hardcoded-tables --enable-libass
--enable-libfdk-aac --enable-libfreetype --enable-libgsm --enable-
libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-
libopenjpeg --enable-libopus --enable-libspeex --enable-libtheora
--enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid
--enable-nonfree --enable-postproc --enable-pthreads --enable-shared
--enable-version3 --extra-libs=-lgcrypt
libavutil 56. 0.100 / 56. 0.100
libavcodec 58. 0.100 / 58. 0.100
libavformat 58. 0.100 / 58. 0.100
libavdevice 58. 0.100 / 58. 0.100
libavfilter 7. 0.100 / 7. 0.100
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 0.100 / 5. 0.100
libswresample 3. 0.100 / 3. 0.100
libpostproc 55. 0.100 / 55. 0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2mp41
encoder : Lavf57.76.100
Duration: 00:00:10.00, start: 0.000000, bitrate: 3528 kb/s
Stream #0:0(eng): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D),
yuv420p, 640x480 [SAR 1:1 DAR 4:3], 3350 kb/s, 25 fps, 25 tbr, 12800 tbn,
25 tbc (default)
Metadata:
handler_name : VideoHandler
Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz,
stereo, fltp, 174 kb/s (default)
Metadata:
handler_name : SoundHandler
Stream mapping:
Stream #0:0 -> #0:0 (mpeg4 (native) -> h264 (libx264))
Stream #0:1 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
[libx264 @ 0x15f6620] using SAR=1/1
[libx264 @ 0x15f6620] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2
[libx264 @ 0x15f6620] profile High, level 3.0
[libx264 @ 0x15f6620] 264 - core 142 r2431 a5831aa - H.264/MPEG-4 AVC
codec - Copyleft 2003-2014 - http://www.videolan.org/x264.html - options:
cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1
psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1
cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=3
lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0
bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1
b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25
scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0
qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
[hls @ 0x15f6040] Opening 'init.mp4' for writing
Output #0, hls, to 'fmp4.m3u8':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2mp41
encoder : Lavf58.0.100
Stream #0:0(eng): Video: h264 (libx264), yuv420p, 640x480 [SAR 1:1 DAR
4:3], q=-1--1, 25 fps, 12800 tbn, 25 tbc (default)
Metadata:
handler_name : VideoHandler
encoder : Lavc58.0.100 libx264
Side data:
cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
Stream #0:1(eng): Audio: aac (LC), 44100 Hz, stereo, fltp, 128 kb/s
(default)
Metadata:
handler_name : SoundHandler
encoder : Lavc58.0.100 aac
[hls @ 0x15f6040] Opening '0.m4s' for writing
[hls @ 0x15f6040] Opening 'fmp4.m3u8.tmp' for writing
[mp4 @ 0x1d9a4a0] Track 1 starts with a nonzero dts 5723, while the moov
already has been written. Set the delay_moov flag to handle this case.
[hls @ 0x15f6040] Opening '1.m4s' for writing0:07.94 bitrate=N/A
speed=2.22x
[hls @ 0x15f6040] Opening 'fmp4.m3u8.tmp' for writing
[hls @ 0x15f6040] Opening '2.m4s' for writing0:09.80 bitrate=N/A
speed=2.13x
[hls @ 0x15f6040] Opening 'fmp4.m3u8.tmp' for writing
[hls @ 0x15f6040] Opening '3.m4s' for writing
[hls @ 0x15f6040] Opening 'fmp4.m3u8.tmp' for writing
[hls @ 0x15f6040] Opening 'fmp4.m3u8.tmp' for writing
frame= 250 fps= 45 q=-1.0 Lsize=N/A time=00:00:10.00 bitrate=N/A speed=
1.8x
video:1229kB audio:115kB subtitle:0kB other streams:0kB global headers:0kB
muxing overhead: unknown
}}}
This creates 0.m4s, 1.m4s, 2.m4s and 3.m4s but the m3u8 does not include
0.m4s. The resulting file therefore misses the first segment:
{{{
#EXTM3U
#EXT-X-VERSION:7
#EXT-X-TARGETDURATION:7
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-MAP:URI="init.mp4"
#EXTINF:1.520000,
1.m4s
#EXTINF:1.280000,
2.m4s
#EXTINF:0.320000,
3.m4s
#EXT-X-ENDLIST
}}}
Using the same ffmpeg command without the `-hls_segment_type fmp4` option
creates mpegts segments (0.ts, 1.ts, 2.ts and 3.ts) and the corresponding
m3u8 includes all segments, so nothing is skipped:
{{{
ffmpeg -i input.mp4 -hls_segment_filename '%d.ts' -f hls mpegts.m3u8
ffmpeg version N-88116-gacf7063 Copyright (c) 2000-2017 the FFmpeg
developers
built with gcc 4.9.2 (Debian 4.9.2-10)
configuration: --prefix=/usr --enable-avfilter --enable-shared --enable-
avresample --enable-gpl --enable-hardcoded-tables --enable-libass
--enable-libfdk-aac --enable-libfreetype --enable-libgsm --enable-
libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-
libopenjpeg --enable-libopus --enable-libspeex --enable-libtheora
--enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid
--enable-nonfree --enable-postproc --enable-pthreads --enable-shared
--enable-version3 --extra-libs=-lgcrypt
libavutil 56. 0.100 / 56. 0.100
libavcodec 58. 0.100 / 58. 0.100
libavformat 58. 0.100 / 58. 0.100
libavdevice 58. 0.100 / 58. 0.100
libavfilter 7. 0.100 / 7. 0.100
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 0.100 / 5. 0.100
libswresample 3. 0.100 / 3. 0.100
libpostproc 55. 0.100 / 55. 0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2mp41
encoder : Lavf57.76.100
Duration: 00:00:10.00, start: 0.000000, bitrate: 3528 kb/s
Stream #0:0(eng): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D),
yuv420p, 640x480 [SAR 1:1 DAR 4:3], 3350 kb/s, 25 fps, 25 tbr, 12800 tbn,
25 tbc (default)
Metadata:
handler_name : VideoHandler
Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz,
stereo, fltp, 174 kb/s (default)
Metadata:
handler_name : SoundHandler
Stream mapping:
Stream #0:0 -> #0:0 (mpeg4 (native) -> h264 (libx264))
Stream #0:1 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
[libx264 @ 0x9dc5c0] using SAR=1/1
[libx264 @ 0x9dc5c0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2
[libx264 @ 0x9dc5c0] profile High, level 3.0
[libx264 @ 0x9dc5c0] 264 - core 142 r2431 a5831aa - H.264/MPEG-4 AVC codec
- Copyleft 2003-2014 - http://www.videolan.org/x264.html - options:
cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1
psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1
cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=3
lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0
bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1
b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25
scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0
qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
[hls @ 0x9dbfe0] Opening '0.ts' for writing
Output #0, hls, to 'mpegts.m3u8':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2mp41
encoder : Lavf58.0.100
Stream #0:0(eng): Video: h264 (libx264), yuv420p, 640x480 [SAR 1:1 DAR
4:3], q=-1--1, 25 fps, 90k tbn, 25 tbc (default)
Metadata:
handler_name : VideoHandler
encoder : Lavc58.0.100 libx264
Side data:
cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
Stream #0:1(eng): Audio: aac (LC), 44100 Hz, stereo, fltp, 128 kb/s
(default)
Metadata:
handler_name : SoundHandler
encoder : Lavc58.0.100 aac
[hls @ 0x9dbfe0] Opening '1.ts' for writing:00:08.75 bitrate=N/A
speed=2.14x
[hls @ 0x9dbfe0] Opening 'mpegts.m3u8.tmp' for writing
[hls @ 0x9dbfe0] Opening '2.ts' for writing:00:09.75 bitrate=N/A
speed=2.12x
[hls @ 0x9dbfe0] Opening 'mpegts.m3u8.tmp' for writing
[hls @ 0x9dbfe0] Opening '3.ts' for writing
[hls @ 0x9dbfe0] Opening 'mpegts.m3u8.tmp' for writing
[hls @ 0x9dbfe0] Opening 'mpegts.m3u8.tmp' for writing
frame= 250 fps= 45 q=-1.0 Lsize=N/A time=00:00:10.00 bitrate=N/A
speed=1.79x
video:1229kB audio:115kB subtitle:0kB other streams:0kB global headers:0kB
muxing overhead: unknown
}}}
resulting m3u8:
{{{
#EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:7
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:6.880000,
0.ts
#EXTINF:1.520000,
1.ts
#EXTINF:1.280000,
2.ts
#EXTINF:0.320000,
3.ts
#EXT-X-ENDLIST
}}}
In this particular example, playing the fmp4 segmented version means the
first 7 seconds are missed, whereas the mpegts segmented video is
complete.
--
Ticket URL: <https://trac.ffmpeg.org/ticket/6776>
FFmpeg <https://ffmpeg.org>
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