[FFmpeg-trac] #7257(undetermined:new): concatenating MP4 files reads all of them twice

FFmpeg trac at avcodec.org
Mon Jun 18 01:06:17 EEST 2018


#7257: concatenating MP4 files reads all of them twice
-------------------------------------+-------------------------------------
             Reporter:  AyrA         |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
              Version:  git-master   |  undetermined
             Keywords:  concat mov   |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0
-------------------------------------+-------------------------------------
Changes (by cehoyos):

 * keywords:   => concat mov


Comment:

 The issue can now be shown with `loglevel verbose`, I don't know if this
 is a bug that can be fixed or an unavoidable limitation of the concat
 demuxer.
 {{{
 $ ffmpeg -loglevel verbose -f concat -i concat.txt -t 1 -f null -
 ffmpeg version N-91317-gb41b6b3 Copyright (c) 2000-2018 the FFmpeg
 developers
   built with gcc 6.4.0 (GCC)
   configuration: --enable-gpl
   libavutil      56. 18.102 / 56. 18.102
   libavcodec     58. 20.102 / 58. 20.102
   libavformat    58. 17.100 / 58. 17.100
   libavdevice    58.  4.101 / 58.  4.101
   libavfilter     7. 25.100 /  7. 25.100
   libswscale      5.  2.100 /  5.  2.100
   libswresample   3.  2.100 /  3.  2.100
   libpostproc    55.  2.100 / 55.  2.100
 [h264 @ 0x3ee14c0] Reinit context to 1920x1088, pix_fmt: yuvj420p
 [mov,mp4,m4a,3gp,3g2,mj2 @ 0x3edf880] Auto-inserting h264_mp4toannexb
 bitstream filter
 [h264 @ 0x3ee52c0] Reinit context to 1920x1088, pix_fmt: yuvj420p
 [concat @ 0x3ed6500] Could not find codec parameters for stream 2
 (Unknown: none): unknown codec
 Consider increasing the value for the 'analyzeduration' and 'probesize'
 options
 [concat @ 0x3ed6500] Could not find codec parameters for stream 3
 (Unknown: none): unknown codec
 Consider increasing the value for the 'analyzeduration' and 'probesize'
 options
 [concat @ 0x3ed6500] Could not find codec parameters for stream 4
 (Unknown: none): unknown codec
 Consider increasing the value for the 'analyzeduration' and 'probesize'
 options
 Input #0, concat, from 'concat.txt':
   Duration: N/A, start: 0.000000, bitrate: 47190 kb/s
     Stream #0:0(eng): Video: h264 (High), 1 reference frame (avc1 /
 0x31637661), yuvj420p(pc, bt709, left), 1920x1080 (1920x1088) [SAR 1:1 DAR
 16:9], 47001 kb/s, 50 fps, 50 tbr, 90k tbn, 100 tbc
     Metadata:
       creation_time   : 2018-06-13T18:00:58.000000Z
       handler_name    : GoPro AVC
       encoder         : GoPro AVC encoder
       timecode        : 18:00:58:12
     Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz,
 stereo, fltp, 189 kb/s
     Metadata:
       creation_time   : 2018-06-13T18:00:58.000000Z
       handler_name    : GoPro AAC
       timecode        : 18:00:58:12
     Stream #0:2: Unknown: none
     Stream #0:3: Unknown: none
     Stream #0:4: Unknown: none
 Stream mapping:
   Stream #0:0 -> #0:0 (h264 (native) -> wrapped_avframe (native))
   Stream #0:1 -> #0:1 (aac (native) -> pcm_s16le (native))
 Press [q] to stop, [?] for help
 [h264 @ 0x4b55840] Reinit context to 1920x1088, pix_fmt: yuvj420p
 [graph_1_in_0_1 @ 0x3f18ec0] tb:1/48000 samplefmt:fltp samplerate:48000
 chlayout:0x3
 [format_out_0_1 @ 0x3f19540] auto-inserting filter 'auto_resampler_0'
 between the filter 'Parsed_anull_0' and the filter 'format_out_0_1'
 [auto_resampler_0 @ 0x3f1a580] ch:2 chl:stereo fmt:fltp r:48000Hz -> ch:2
 chl:stereo fmt:s16 r:48000Hz
 [graph 0 input from stream 0:0 @ 0x3f2fd80] w:1920 h:1080 pixfmt:yuvj420p
 tb:1/90000 fr:50/1 sar:1/1 sws_param:flags=2
 Output #0, null, to 'pipe:':
   Metadata:
     encoder         : Lavf58.17.100
     Stream #0:0(eng): Video: wrapped_avframe, 1 reference frame,
 yuvj420p(left), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 50 fps, 50
 tbn, 50 tbc
     Metadata:
       creation_time   : 2018-06-13T18:00:58.000000Z
       handler_name    : GoPro AVC
       timecode        : 18:00:58:12
       encoder         : Lavc58.20.102 wrapped_avframe
     Stream #0:1(eng): Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
     Metadata:
       creation_time   : 2018-06-13T18:00:58.000000Z
       handler_name    : GoPro AAC
       timecode        : 18:00:58:12
       encoder         : Lavc58.20.102 pcm_s16le
 No more output streams to write to, finishing.:01.00 bitrate=N/A
 speed=0.0226x
 frame=   50 fps=1.1 q=-0.0 Lsize=N/A time=00:00:01.00 bitrate=N/A
 speed=0.0224x
 video:26kB audio:188kB subtitle:0kB other streams:0kB global headers:0kB
 muxing overhead: unknown
 Input file #0 (concat.txt):
   Input stream #0:0 (video): 59 packets read (7258062 bytes); 52 frames
 decoded;
   Input stream #0:1 (audio): 55 packets read (27760 bytes); 55 frames
 decoded (56320 samples);
   Input stream #0:2 ((null)): 1 packets read (4 bytes);
   Input stream #0:3 ((null)): 1 packets read (4428 bytes);
   Input stream #0:4 ((null)): 66362 packets read (1062472 bytes);
   Total: 66478 packets (8352726 bytes) demuxed
 Output file #0 (pipe:):
   Output stream #0:0 (video): 50 frames encoded; 50 packets muxed (26800
 bytes);
   Output stream #0:1 (audio): 47 frames encoded (48000 samples); 47
 packets muxed (192000 bytes);
   Total: 97 packets (218800 bytes) muxed
 [AVIOContext @ 0x3ee8100] Statistics: 1117648442 bytes read, 33854 seeks
 [AVIOContext @ 0x3ed6c80] Statistics: 19 bytes read, 0 seeks
 }}}
 {{{
 $ ffmpeg -loglevel verbose -i GH010051.MP4 -t 1 -f null -
 ffmpeg version N-91317-gb41b6b3 Copyright (c) 2000-2018 the FFmpeg
 developers
   built with gcc 6.4.0 (GCC)
   configuration: --enable-gpl
   libavutil      56. 18.102 / 56. 18.102
   libavcodec     58. 20.102 / 58. 20.102
   libavformat    58. 17.100 / 58. 17.100
   libavdevice    58.  4.101 / 58.  4.101
   libavfilter     7. 25.100 /  7. 25.100
   libswscale      5.  2.100 /  5.  2.100
   libswresample   3.  2.100 /  3.  2.100
   libpostproc    55.  2.100 / 55.  2.100
 [h264 @ 0x3c00700] Reinit context to 1920x1088, pix_fmt: yuvj420p
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'GH010051.MP4':
   Metadata:
     major_brand     : mp41
     minor_version   : 538120216
     compatible_brands: mp41
     creation_time   : 2018-06-13T18:00:58.000000Z
     firmware        : HD6.01.02.01.00
   Duration: 00:11:18.02, start: 0.000000, bitrate: 47250 kb/s
     Stream #0:0(eng): Video: h264 (High), 1 reference frame (avc1 /
 0x31637661), yuvj420p(pc, bt709, left), 1920x1080 (1920x1088) [SAR 1:1 DAR
 16:9], 47001 kb/s, 50 fps, 50 tbr, 90k tbn, 100 tbc (default)
     Metadata:
       creation_time   : 2018-06-13T18:00:58.000000Z
       handler_name    : GoPro AVC
       encoder         : GoPro AVC encoder
       timecode        : 18:00:58:12
     Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz,
 stereo, fltp, 189 kb/s (default)
     Metadata:
       creation_time   : 2018-06-13T18:00:58.000000Z
       handler_name    : GoPro AAC
       timecode        : 18:00:58:12
     Stream #0:2(eng): Data: none (tmcd / 0x64636D74) (default)
     Metadata:
       creation_time   : 2018-06-13T18:00:58.000000Z
       handler_name    : GoPro TCD
       timecode        : 18:00:58:12
     Stream #0:3(eng): Data: none (gpmd / 0x646D7067), 35 kb/s (default)
     Metadata:
       creation_time   : 2018-06-13T18:00:58.000000Z
       handler_name    : GoPro MET
     Stream #0:4(eng): Data: none (fdsc / 0x63736466), 12 kb/s (default)
     Metadata:
       creation_time   : 2018-06-13T18:00:58.000000Z
       handler_name    : GoPro SOS
 Stream mapping:
   Stream #0:0 -> #0:0 (h264 (native) -> wrapped_avframe (native))
   Stream #0:1 -> #0:1 (aac (native) -> pcm_s16le (native))
 Press [q] to stop, [?] for help
 [h264 @ 0x3c273c0] Reinit context to 1920x1088, pix_fmt: yuvj420p
 [graph_1_in_0_1 @ 0x3eb04c0] tb:1/48000 samplefmt:fltp samplerate:48000
 chlayout:0x3
 [format_out_0_1 @ 0x3eb0e40] auto-inserting filter 'auto_resampler_0'
 between the filter 'Parsed_anull_0' and the filter 'format_out_0_1'
 [auto_resampler_0 @ 0x3eb2340] ch:2 chl:stereo fmt:fltp r:48000Hz -> ch:2
 chl:stereo fmt:s16 r:48000Hz
 [graph 0 input from stream 0:0 @ 0x4665580] w:1920 h:1080 pixfmt:yuvj420p
 tb:1/90000 fr:50/1 sar:1/1 sws_param:flags=2
 Output #0, null, to 'pipe:':
   Metadata:
     major_brand     : mp41
     minor_version   : 538120216
     compatible_brands: mp41
     firmware        : HD6.01.02.01.00
     encoder         : Lavf58.17.100
     Stream #0:0(eng): Video: wrapped_avframe, 1 reference frame,
 yuvj420p(left), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 50 fps, 50
 tbn, 50 tbc (default)
     Metadata:
       creation_time   : 2018-06-13T18:00:58.000000Z
       handler_name    : GoPro AVC
       timecode        : 18:00:58:12
       encoder         : Lavc58.20.102 wrapped_avframe
     Stream #0:1(eng): Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
 (default)
     Metadata:
       creation_time   : 2018-06-13T18:00:58.000000Z
       handler_name    : GoPro AAC
       timecode        : 18:00:58:12
       encoder         : Lavc58.20.102 pcm_s16le
 No more output streams to write to, finishing.
 frame=   50 fps=0.0 q=-0.0 Lsize=N/A time=00:00:01.00 bitrate=N/A
 speed=4.76x
 video:26kB audio:188kB subtitle:0kB other streams:0kB global headers:0kB
 muxing overhead: unknown
 Input file #0 (GH010051.MP4):
   Input stream #0:0 (video): 59 packets read (7257987 bytes); 52 frames
 decoded;
   Input stream #0:1 (audio): 55 packets read (27760 bytes); 55 frames
 decoded (56320 samples);
   Input stream #0:2 (data): 1 packets read (4 bytes);
   Input stream #0:3 (data): 0 packets read (0 bytes);
   Input stream #0:4 (data): 4 packets read (744 bytes);
   Total: 119 packets (7286495 bytes) demuxed
 Output file #0 (pipe:):
   Output stream #0:0 (video): 50 frames encoded; 50 packets muxed (26800
 bytes);
   Output stream #0:1 (audio): 47 frames encoded (48000 samples); 47
 packets muxed (192000 bytes);
   Total: 97 packets (218800 bytes) muxed
 [AVIOContext @ 0x3c07180] Statistics: 8451658 bytes read, 4 seeks
 }}}
 The seeks/reads take considerable time, concat.txt contains only the line
 `file GH010051.MP4`, remuxing the input file with FFmpeg fixes the issue.

--
Ticket URL: <https://trac.ffmpeg.org/ticket/7257#comment:9>
FFmpeg <https://ffmpeg.org>
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