我想使用ffmpeg为MOV文件增加一个无声音轨。
我创建了一个比视频更长的无声音轨,并打算使用ffmpeg的-shortest选项。
使用SoX v14.3.1,我运行以下命令生成wav文件:
sox -n -r 44100 -b 16 -c 2 -L silence.wav trim 0.0 60.000
# -n = Sox's null file
# -r = sample rate
# -b = bits per sample
# -c = num of channels
# -L = little endian
# filename
# trim - is an effect, args start and length.
我的基本ffmpeg命令如下:
ffmpeg -shortest \
-i silence.wav -acodec pcm_s16le \
-i vid_no_sound.mov -vcodec copy vid_with_sound.mov
这的结果是:ffmpeg version 0.11.1 Copyright (c) 2000-2012 the FFmpeg developers
built on Aug 27 2012 13:11:25 with gcc 4.4.5
configuration: --extra-cflags=-static --prefix=/root/ffmpeg_build/src/ffmpeg-0.11.1 --enable-bzlib --enable-gnutls --enable-libfreetype --enable-libmp3lame --enable-libdc1394 --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --enable-openssl --enable-zlib --enable-gpl --enable-nonfree --enable-version3
libavutil 51. 54.100 / 51. 54.100
libavcodec 54. 23.100 / 54. 23.100
libavformat 54. 6.100 / 54. 6.100
libavdevice 54. 0.100 / 54. 0.100
libavfilter 2. 77.100 / 2. 77.100
libswscale 2. 1.100 / 2. 1.100
libswresample 0. 15.100 / 0. 15.100
libpostproc 52. 0.100 / 52. 0.100
[wav @ 0x29ab2e0] max_analyze_duration 5000000 reached at 5015510
Guessed Channel Layout for Input Stream #0.0 : stereo
Input #0, wav, from 'silence.wav':
Duration: 00:01:00.00, bitrate: 1411 kb/s
Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, stereo, s16, 1411 kb/s
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'vid_no_sound.mov':
Metadata:
major_brand : qt
minor_version : 537199360
compatible_brands: qt
creation_time : 2012-07-25 13:41:44
Duration: 00:00:14.50, start: 0.000000, bitrate: 27457 kb/s
Stream #1:0(eng): Video: qtrle (rle / 0x20656C72), rgb24, 1920x1080, 27450 kb/s, SAR 1920:1920 DAR 16:9, 24 fps, 24 tbr, 24 tbn, 24 tbc
Metadata:
creation_time : 2012-07-25 13:41:44
handler_name : Apple Alias Data Handler
Stream #1:1(eng): Data: none (tmcd / 0x64636D74)
Metadata:
creation_time : 2012-07-25 13:42:06
handler_name : Apple Alias Data Handler
timecode : 00:00:00:00
File 'vid_with_sound.mov' already exists. Overwrite ? [y/N] y
auto-inserting filter 'auto-inserted resampler 0' between the filter 'src' and the filter 'aformat'
[aresample @ 0x2ab3b00] chl:stereo fmt:s16 r:44100Hz -> chl:stereo fmt:flt r:44100Hz
[NULL @ 0x2994320] Codec is experimental but experimental codecs are not enabled, try -strict -2
Output #0, mov, to 'vid_with_sound.mov':
Stream #0:0(eng): Video: qtrle (rle / 0x20656C72), rgb24, 1920x1080 [SAR 1920:1920 DAR 16:9], q=2-31, 27450 kb/s, 24 fps, 90k tbn, 24 tbc
Metadata:
creation_time : 2012-07-25 13:41:44
handler_name : Apple Alias Data Handler
Stream #0:1: Audio: none, 44100 Hz, stereo, flt, 128 kb/s
Stream mapping:
Stream #1:0 -> #0:0 (copy)
Stream #0:0 -> #0:1 (pcm_s16le -> aac)
Error while opening encoder for output stream #0:1 - maybe incorrect parameters such as bit_rate, rate, width or height
我尝试按照建议添加-strict -2
,但是我不确定在命令行中应该放在哪里。
我已经尝试了两个小时不同的方法,并阅读了ffmpeg文档,但还是无法解决问题。
如何给mov文件添加一个静音音轨?
/dev/zero
在avconv
中也可以使用,但-f lavfi
似乎不行。别忘了加上-shortest
标志,否则它会一直编码静音。 - z0r