#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>
FFmpeg issue tracker
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