[FFmpeg-trac] #2245(undetermined:new): Speed difference when using -ss on similar MKVs when extracting frame image
FFmpeg
trac at avcodec.org
Thu Feb 7 10:36:43 CET 2013
#2245: Speed difference when using -ss on similar MKVs when extracting frame image
-------------------------------------+-------------------------------------
Reporter: eelco | Type: defect
Status: new | Priority: normal
Component: | Version: git-
undetermined | master
Keywords: | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Summary of the bug:
When using -ss on the input file, some MKVs are significantly slower than
others, while they’re the same resolution. I would expect a small speed
difference due to encoding differences, but in this case it’s about 6-8
times.
How to reproduce:
{{{
> time ./ffmpeg "-ss" "10" "-i" ~/Desktop/ffmpeg-ss-bug/slow-ss.mkv "-f"
"image2" "-vframes" "1" /dev/null
ffmpeg version N-49666-g4745194 Copyright (c) 2000-2013 the FFmpeg
developers
built on Feb 7 2013 10:22:14 with llvm-gcc 4.2.1 (LLVM build
2336.11.00)
configuration: --prefix=/Users/eelco/Projects/Beamer/FFmpeg/build
--enable-gpl --enable-version3 --enable-libx264 --disable-shared --enable-
static --enable-libtheora --enable-libvorbis --enable-libvo-aacenc
--disable-doc --extra-cflags='-DMACOSX_DEPLOYMENT_TARGET=10.6 -isysroot
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk
-mmacosx-version-min=10.6
-I/Users/eelco/Projects/Beamer/FFmpeg/build/include' --extra-
ldflags='-isysroot
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk
-mmacosx-version-min=10.6 -L/Users/eelco/Projects/Beamer/FFmpeg/build/lib'
libavutil 52. 17.101 / 52. 17.101
libavcodec 54. 91.101 / 54. 91.101
libavformat 54. 61.104 / 54. 61.104
libavdevice 54. 3.103 / 54. 3.103
libavfilter 3. 35.101 / 3. 35.101
libswscale 2. 2.100 / 2. 2.100
libswresample 0. 17.102 / 0. 17.102
libpostproc 52. 2.100 / 52. 2.100
Input #0, matroska,webm, from '/Users/eelco/Desktop/ffmpeg-ss-bug/slow-
ss.mkv':
Metadata:
ENCODER : Lavf54.59.106
Duration: 00:00:11.22, start: 0.000000, bitrate: 9890 kb/s
Chapter #0.0: start 0.000000, end 11.000000
Metadata:
title : 00:00:00.000
Stream #0:0(eng): Video: h264 (High), yuv420p, 1920x1080, SAR 1:1 DAR
16:9, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
Stream #0:1(eng): Audio: truehd, 48000 Hz, 7.1, s32 (default)
Metadata:
title : English TRUE-HD
LANGUAGE : eng
Output #0, image2, to '/dev/null':
Metadata:
encoder : Lavf54.61.104
Chapter #0.0: start 0.000000, end 1.000000
Metadata:
title : 00:00:00.000
Stream #0:0(eng): Video: mjpeg, yuvj420p, 1920x1080 [SAR 1:1 DAR
16:9], q=2-31, 200 kb/s, 90k tbn, 23.98 tbc (default)
Stream mapping:
Stream #0:0 -> #0:0 (h264 -> mjpeg)
Press [q] to stop, [?] for help
frame= 1 fps=0.4 q=0.0 Lsize=N/A time=00:00:00.04 bitrate=N/A dup=0
drop=236
video:50kB audio:0kB subtitle:0 global headers:0kB muxing overhead
-100.043320%
2.41 real 5.94 user 0.10 sys
}}}
VS.
{{{
> time ./ffmpeg "-ss" "10" "-i" ~/Desktop/ffmpeg-ss-bug/fast-ss.mkv "-f"
"image2" "-vframes" "1" /dev/null
ffmpeg version N-49666-g4745194 Copyright (c) 2000-2013 the FFmpeg
developers
built on Feb 7 2013 10:22:14 with llvm-gcc 4.2.1 (LLVM build
2336.11.00)
configuration: --prefix=/Users/eelco/Projects/Beamer/FFmpeg/build
--enable-gpl --enable-version3 --enable-libx264 --disable-shared --enable-
static --enable-libtheora --enable-libvorbis --enable-libvo-aacenc
--disable-doc --extra-cflags='-DMACOSX_DEPLOYMENT_TARGET=10.6 -isysroot
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk
-mmacosx-version-min=10.6
-I/Users/eelco/Projects/Beamer/FFmpeg/build/include' --extra-
ldflags='-isysroot
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk
-mmacosx-version-min=10.6 -L/Users/eelco/Projects/Beamer/FFmpeg/build/lib'
libavutil 52. 17.101 / 52. 17.101
libavcodec 54. 91.101 / 54. 91.101
libavformat 54. 61.104 / 54. 61.104
libavdevice 54. 3.103 / 54. 3.103
libavfilter 3. 35.101 / 3. 35.101
libswscale 2. 2.100 / 2. 2.100
libswresample 0. 17.102 / 0. 17.102
libpostproc 52. 2.100 / 52. 2.100
Input #0, matroska,webm, from '/Users/eelco/Desktop/ffmpeg-ss-bug/fast-
ss.mkv':
Metadata:
MAJOR_BRAND : qt
MINOR_VERSION : 537199360
COMPATIBLE_BRANDS: qt
TIMECODE : 00:00:00:00
ENCODER : Lavf54.59.106
Duration: 00:00:11.08, start: 0.000000, bitrate: 14054 kb/s
Stream #0:0(eng): Video: h264 (Main), yuv420p, 1920x1080, SAR 1:1 DAR
16:9, 24 fps, 24 tbr, 1k tbn, 2k tbc (default)
Metadata:
CREATION_TIME : 2008-05-27 18:40:35
LANGUAGE : eng
HANDLER_NAME : Apple Alias Data Handler
Stream #0:1(eng): Audio: aac, 48000 Hz, 5.1, fltp (default)
Metadata:
CREATION_TIME : 2008-05-27 18:40:35
LANGUAGE : eng
HANDLER_NAME : Apple Alias Data Handler
Output #0, image2, to '/dev/null':
Metadata:
MAJOR_BRAND : qt
MINOR_VERSION : 537199360
COMPATIBLE_BRANDS: qt
TIMECODE : 00:00:00:00
encoder : Lavf54.61.104
Stream #0:0(eng): Video: mjpeg, yuvj420p, 1920x1080 [SAR 1:1 DAR
16:9], q=2-31, 200 kb/s, 90k tbn, 24 tbc (default)
Metadata:
CREATION_TIME : 2008-05-27 18:40:35
LANGUAGE : eng
HANDLER_NAME : Apple Alias Data Handler
Stream mapping:
Stream #0:0 -> #0:0 (h264 -> mjpeg)
Press [q] to stop, [?] for help
frame= 1 fps=0.0 q=0.0 Lsize=N/A time=00:00:00.04 bitrate=N/A dup=0
drop=21
video:205kB audio:0kB subtitle:0 global headers:0kB muxing overhead
-100.010488%
0.42 real 0.70 user 0.07 sys
}}}
I’ll upload the sample files to the FTP server.
--
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2245>
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