Hello, I'm using the -ss and -t flags to trim a section of video out of a longer original one. As an example, if the video is 60 minutes long, and I want minutes 50-52, ffmpeg takes quite a while to get to that point. I'll see something like the following (I know my -ss flag values don't exactly match my example)
Users-MacBook-Pro:ffmpeg-0.10 user$ ./ffmpeg -i "Long GOPRO.MP4" -vcodec copy -acodec copy -ss 0:05:10 -t 0:00:30 "output1.mp4" ffmpeg version 0.10 Copyright (c) 2000-2012 the FFmpeg developers built on Jan 30 2012 11:07:22 with llvm_gcc 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.1.00) configuration: --enable-static --disable-shared --disable-outdev=sdl --enable-runtime-cpudetect --disable-bzlib --disable-libfreetype --disable-libopenjpeg --enable-zlib --arch=x86_64 --sysroot=/Developer/SDKs/MacOSX10.7.sdk --extra-cflags='-isysroot /Developer/SDKs/MacOSX10.7.sdk -DMACOSX_DEPLOYMENT_TARGET=10.5 -mmacosx-version-min=10.5' libavutil 51. 34.101 / 51. 34.101 libavcodec 53. 60.100 / 53. 60.100 libavformat 53. 31.100 / 53. 31.100 libavdevice 53. 4.100 / 53. 4.100 libavfilter 2. 60.100 / 2. 60.100 libswscale 2. 1.100 / 2. 1.100 libswresample 0. 6.100 / 0. 6.100 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Long GOPRO.MP4': Metadata: major_brand : avc1 minor_version : 0 compatible_brands: avc1isom creation_time : 2011-07-09 14:44:04 Duration: 00:34:39.07, start: 0.000000, bitrate: 15151 kb/s Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 15008 kb/s, 59.94 fps, 59.94 tbr, 90k tbn, 119.88 tbc Metadata: creation_time : 2011-07-09 14:44:04 handler_name : GoPro AVC Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, s16, 128 kb/s Metadata: creation_time : 2011-07-09 14:44:04 handler_name : GoPro AAC Output #0, mp4, to 'output1.mp4': Metadata: major_brand : avc1 minor_version : 0 compatible_brands: avc1isom creation_time : 2011-07-09 14:44:04 encoder : Lavf53.31.100 Stream #0:0(eng): Video: h264 (![0][0][0] / 0x0021), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], q=2-31, 15008 kb/s, 59.94 fps, 90k tbn, 90k tbc Metadata: creation_time : 2011-07-09 14:44:04 handler_name : GoPro AVC Stream #0:1(eng): Audio: aac (@[0][0][0] / 0x0040), 48000 Hz, stereo, 128 kb/s Metadata: creation_time : 2011-07-09 14:44:04 handler_name : GoPro AAC Stream mapping: Stream #0:0 -> #0:0 (copy) Stream #0:1 -> #0:1 (copy) Press [q] to stop, [?] for help frame= 0 fps= 0 q=-1.0 q=-1.0 q=-1.0 size= 0kB time=00:00:00.00 bitrate= 0 frame= 0 fps= 0 q=-1.0 q=-1.0 q=-1.0 size= 0kB time=00:00:00.00 bitrate= 0 frame= 0 fps= 0 q=-1.0 q=-1.0 q=-1.0 size= 0kB time=00:00:00.00 bitrate= 0 frame= 0 fps= 0 q=-1.0 q=-1.0 q=-1.0 size= 0kB time=00:00:00.00 bitrate= 0 frame= 0 fps= 0 q=-1.0 q=-1.0 q=-1.0 size= 0kB time=00:00:00.00 bitrate= 0 frame= 0 fps= 0 q=-1.0 q=-1.0 q=-1.0 size= 0kB time=00:00:00.00 bitrate= 0 frame= 0 fps= 0 q=-1.0 q=-1.0 q=-1.0 size= 0kB time=00:00:00.00 bitrate= 0 frame= 0 fps= 0 q=-1.0 q=-1.0 q=-1.0 size= 0kB time=00:00:00.00 bitrate= 0 frame= 0 fps= 0 q=-1.0 q=-1.0 q=-1.0 size= 0kB time=00:00:00.00 bitrate= 0 frame= 0 fps= 0 q=-1.0 q=-1.0 q=-1.0 size= 0kB time=00:00:00.00 bitrate= 0 frame= 0 fps= 0 q=-1.0 q=-1.0 q=-1.0 size= 0kB time=00:00:00.00 bitrate= 0 frame= 0 fps= 0 q=-1.0 q=-1.0 q=-1.0 size= 0kB time=00:00:00.00 bitrate= 0 frame= 0 fps= 0 q=-1.0 q=-1.0 q=-1.0 size= 0kB time=00:00:00.00 bitrate= 0 frame= 212 fps= 25 q=-1.0 q=-1.0 q=-1.0 size= 6632kB time=00:00:00.00 bitrate= 0 frame= 482 fps= 53 q=-1.0 q=-1.0 q=-1.0 size= 14892kB time=00:00:00.00 bitrate= 0 frame= 781 fps= 81 q=-1.0 q=-1.0 q=-1.0 size= 24175kB time=00:00:03.30 bitrate=5989 ... My complaint is that ffmpeg will spew out "frame= 0 fps= 0 q=-1.0 q=-1.0 q=-1.0 size= 0kB time=00:00:00.00 bitrate= 0" for several minutes until it reaches the point at which it should start trimming. The farther the point of trimming, the longer it takes to seek to that point. Is there any way to speed this up? If I play the video manually, I can jump to minute 50 instantly by dragging the playhead. Therefore, why does ffmpeg take so long to get there? Thanks in advance! Simon _______________________________________________ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user