[FFmpeg-user] split audio/video and merge later gets async
Mike Martin
mike at redtux.org.uk
Tue Oct 15 14:32:54 CEST 2013
Someone can correct me, but at least with async (deprecated I know) you
have to place it before input ie ffmpeg -async 24 -i <input file> <opts?
<outfile>
On 2 September 2013 14:41, Frank Tetzel <s1445051 at mail.zih.tu-dresden.de>wrote:
> > > Even if i don't process the audio file (except convert to wav).
> > > Just splitting and merging gets out of sync.
> > > $ ffmpeg -i grab.mkv -vn -c:a pcm_s16le grab-aud.wav
> > > $ ffmpeg -i grab.mkv -i grab-aud.wav -map 0:0 -map 1:0 -c copy
> > > merge.mkv
> >
> > Complete, uncut console output missing.
>
> See end of message.
>
> > Audio in mkv probably has a delay which cannot be saved in wav,
> > I don't think anything except finding out the delay and using
> > it when remuxing (itsoffset) is possible.
>
> The delay isn't constant. The gap seems to get bigger over time, audio
> before video.
>
> Besides, how do i find out the delay? ffprobe (-show_streams) doesn't
> help me here (see end of message).
>
> > Which audio filter is missing in FFmpeg?
>
> A filter for noise reduction would be handy. sox noisered does a good
> job, similar to audacity.
>
> Regards,
> Frank.
>
>
> (I rebuilt ffmpeg recently to enable libfdk-aac and libaacplus. The
> recording was done without it. The problem was already there.)
>
> $ ffmpeg -i grab.mkv -vn -c:a pcm_s16le grab-aud.wav
> ffmpeg version 2.0.1 Copyright (c) 2000-2013 the FFmpeg developers
> built on Sep 1 2013 19:33:37 with gcc 4.8.1 (GCC) 20130725 (prerelease)
> configuration: --prefix=/usr --disable-debug --disable-static
> --enable-avresample --enable-dxva2 --enable-fontconfig --enable-gpl
> --enable-libass --enable-libbluray --enable-libfreetype --enable-libgsm
> --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb
> --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus
> --enable-libpulse --enable-librtmp --enable-libschroedinger
> --enable-libspeex --enable-libtheora --enable-libv4l2 --enable-libvorbis
> --enable-libvpx --enable-libx264 --enable-libxvid --enable-pic
> --enable-postproc --enable-runtime-cpudetect --enable-shared
> --enable-swresample --enable-vdpau --enable-version3 --enable-x11grab
> --enable-libaacplus --enable-libfdk-aac --enable-nonfree
> libavutil 52. 38.100 / 52. 38.100
> libavcodec 55. 18.102 / 55. 18.102
> libavformat 55. 12.100 / 55. 12.100
> libavdevice 55. 3.100 / 55. 3.100
> libavfilter 3. 79.101 / 3. 79.101
> libavresample 1. 1. 0 / 1. 1. 0
> libswscale 2. 3.100 / 2. 3.100
> libswresample 0. 17.102 / 0. 17.102
> libpostproc 52. 3.100 / 52. 3.100
> Input #0, matroska,webm, from 'grab.mkv':
> Metadata:
> ENCODER : Lavf55.12.100
> Duration: 01:05:21.04, start: 0.000000, bitrate: 754 kb/s
> Stream #0:0: Video: h264 (High 4:4:4 Predictive), yuv444p, 798x438,
> SAR 1:1 DAR 133:73, 25 fps, 25 tbr, 1k tbn, 50 tbc (default)
> Stream #0:1: Audio: flac, 44100 Hz, mono, s16 (default)
> Output #0, wav, to 'grab-aud.wav':
> Metadata:
> ISFT : Lavf55.12.100
> Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, mono,
> s16, 705 kb/s (default)
> Stream mapping:
> Stream #0:1 -> #0:0 (flac -> pcm_s16le)
> Press [q] to stop, [?] for help
> size= 337437kB time=01:05:20.94 bitrate= 705.0kbits/s
> video:0kB audio:337437kB subtitle:0 global headers:0kB muxing overhead
> 0.000023%
>
> $ ffmpeg -i grab.mkv -i grab-aud.wav -map 0:0,0:0 -map 1:0,0:0 -c copy
> merge.mkv
> ffmpeg version 2.0.1 Copyright (c) 2000-2013 the FFmpeg developers
> built on Sep 1 2013 19:33:37 with gcc 4.8.1 (GCC) 20130725 (prerelease)
> configuration: --prefix=/usr --disable-debug --disable-static
> --enable-avresample --enable-dxva2 --enable-fontconfig --enable-gpl
> --enable-libass --enable-libbluray --enable-libfreetype --enable-libgsm
> --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb
> --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus
> --enable-libpulse --enable-librtmp --enable-libschroedinger
> --enable-libspeex --enable-libtheora --enable-libv4l2 --enable-libvorbis
> --enable-libvpx --enable-libx264 --enable-libxvid --enable-pic
> --enable-postproc --enable-runtime-cpudetect --enable-shared
> --enable-swresample --enable-vdpau --enable-version3 --enable-x11grab
> --enable-libaacplus --enable-libfdk-aac --enable-nonfree
> libavutil 52. 38.100 / 52. 38.100
> libavcodec 55. 18.102 / 55. 18.102
> libavformat 55. 12.100 / 55. 12.100
> libavdevice 55. 3.100 / 55. 3.100
> libavfilter 3. 79.101 / 3. 79.101
> libavresample 1. 1. 0 / 1. 1. 0
> libswscale 2. 3.100 / 2. 3.100
> libswresample 0. 17.102 / 0. 17.102
> libpostproc 52. 3.100 / 52. 3.100
> Input #0, matroska,webm, from 'grab.mkv':
> Metadata:
> ENCODER : Lavf55.12.100
> Duration: 01:05:21.04, start: 0.000000, bitrate: 754 kb/s
> Stream #0:0: Video: h264 (High 4:4:4 Predictive), yuv444p, 798x438,
> SAR 1:1 DAR 133:73, 25 fps, 25 tbr, 1k tbn, 50 tbc (default)
> Stream #0:1: Audio: flac, 44100 Hz, mono, s16 (default)
> Guessed Channel Layout for Input Stream #1.0 : mono
> Input #1, wav, from 'grab-aud.wav':
> Metadata:
> encoder : Lavf55.12.100
> Duration: 01:05:17.64, bitrate: 705 kb/s
> Stream #1:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, mono,
> s16, 705 kb/s
> Output #0, matroska, to 'merge.mkv':
> Metadata:
> encoder : Lavf55.12.100
> Stream #0:0: Video: h264 (H264 / 0x34363248), yuv444p, 798x438 [SAR
> 1:1 DAR 133:73], q=2-31, 25 fps, 1k tbn, 1k tbc (default)
> Stream #0:1: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, mono,
> 705 kb/s
> Stream mapping:
> Stream #0:0 -> #0:0 (copy)
> Stream #1:0 -> #0:1 (copy)
> Press [q] to stop, [?] for help
> frame=98026 fps=52546 q=-1.0 Lsize= 508544kB time=01:05:21.00
> bitrate=1062.5kbits/s
> video:169839kB audio:337437kB subtitle:0 global headers:0kB muxing
> overhead 0.249911%
>
> $ ffprobe -show_streams grab.mkv
> ffprobe version 2.0.1 Copyright (c) 2007-2013 the FFmpeg developers
> built on Sep 1 2013 19:33:37 with gcc 4.8.1 (GCC) 20130725 (prerelease)
> configuration: --prefix=/usr --disable-debug --disable-static
> --enable-avresample --enable-dxva2 --enable-fontconfig --enable-gpl
> --enable-libass --enable-libbluray --enable-libfreetype --enable-libgsm
> --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb
> --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus
> --enable-libpulse --enable-librtmp --enable-libschroedinger
> --enable-libspeex --enable-libtheora --enable-libv4l2 --enable-libvorbis
> --enable-libvpx --enable-libx264 --enable-libxvid --enable-pic
> --enable-postproc --enable-runtime-cpudetect --enable-shared
> --enable-swresample --enable-vdpau --enable-version3 --enable-x11grab
> --enable-libaacplus --enable-libfdk-aac --enable-nonfree
> libavutil 52. 38.100 / 52. 38.100
> libavcodec 55. 18.102 / 55. 18.102
> libavformat 55. 12.100 / 55. 12.100
> libavdevice 55. 3.100 / 55. 3.100
> libavfilter 3. 79.101 / 3. 79.101
> libavresample 1. 1. 0 / 1. 1. 0
> libswscale 2. 3.100 / 2. 3.100
> libswresample 0. 17.102 / 0. 17.102
> libpostproc 52. 3.100 / 52. 3.100
> Input #0, matroska,webm, from 'grab.mkv':
> Metadata:
> ENCODER : Lavf55.12.100
> Duration: 01:05:21.04, start: 0.000000, bitrate: 754 kb/s
> Stream #0:0: Video: h264 (High 4:4:4 Predictive), yuv444p, 798x438,
> SAR 1:1 DAR 133:73, 25 fps, 25 tbr, 1k tbn, 50 tbc (default)
> Stream #0:1: Audio: flac, 44100 Hz, mono, s16 (default)
> [STREAM]
> index=0
> codec_name=h264
> codec_long_name=H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
> profile=High 4:4:4 Predictive
> codec_type=video
> codec_time_base=1/50
> codec_tag_string=[0][0][0][0]
> codec_tag=0x0000
> width=798
> height=438
> has_b_frames=0
> sample_aspect_ratio=1:1
> display_aspect_ratio=133:73
> pix_fmt=yuv444p
> level=30
> timecode=N/A
> id=N/A
> r_frame_rate=25/1
> avg_frame_rate=25/1
> time_base=1/1000
> start_pts=0
> start_time=0.000000
> duration_ts=N/A
> duration=N/A
> bit_rate=N/A
> nb_frames=N/A
> nb_read_frames=N/A
> nb_read_packets=N/A
> DISPOSITION:default=1
> DISPOSITION:dub=0
> DISPOSITION:original=0
> DISPOSITION:comment=0
> DISPOSITION:lyrics=0
> DISPOSITION:karaoke=0
> DISPOSITION:forced=0
> DISPOSITION:hearing_impaired=0
> DISPOSITION:visual_impaired=0
> DISPOSITION:clean_effects=0
> DISPOSITION:attached_pic=0
> [/STREAM]
> [STREAM]
> index=1
> codec_name=flac
> codec_long_name=FLAC (Free Lossless Audio Codec)
> profile=unknown
> codec_type=audio
> codec_time_base=1/44100
> codec_tag_string=[0][0][0][0]
> codec_tag=0x0000
> sample_fmt=s16
> sample_rate=44100
> channels=1
> bits_per_sample=0
> id=N/A
> r_frame_rate=0/0
> avg_frame_rate=0/0
> time_base=1/1000
> start_pts=0
> start_time=0.000000
> duration_ts=N/A
> duration=N/A
> bit_rate=N/A
> nb_frames=N/A
> nb_read_frames=N/A
> nb_read_packets=N/A
> DISPOSITION:default=1
> DISPOSITION:dub=0
> DISPOSITION:original=0
> DISPOSITION:comment=0
> DISPOSITION:lyrics=0
> DISPOSITION:karaoke=0
> DISPOSITION:forced=0
> DISPOSITION:hearing_impaired=0
> DISPOSITION:visual_impaired=0
> DISPOSITION:clean_effects=0
> DISPOSITION:attached_pic=0
> [/STREAM]
> _______________________________________________
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>
More information about the ffmpeg-user
mailing list