Fix entry on concatenating multiple yuv4mpegpipe streams.

patch by John Van Sickle, john.vansickle gmail com

Originally committed as revision 21033 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
John Van Sickle 2010-01-06 13:49:31 +00:00 committed by Diego Biurrun
parent 418a287cae
commit 7659712749
1 changed files with 6 additions and 1 deletions

View File

@ -316,6 +316,11 @@ ffmpeg -f mpeg -i - -sameq -vcodec mpeg4 -acodec libmp3lame output.avi
Similarly, the yuv4mpegpipe format, and the raw video, raw audio codecs also
allow concatenation, and the transcoding step is almost lossless.
When using multiple yuv4mpegpipe(s), the first line needs to be discarded
from all but the first stream. This can be accomplished by piping through
@code{tail} as seen below. Note that when piping through @code{tail} you
must use command grouping, @code{@{ ;@}}, to background properly.
For example, let's say we want to join two FLV files into an output.flv file:
@ -329,7 +334,7 @@ mkfifo all.v
ffmpeg -i input1.flv -vn -f u16le -acodec pcm_s16le -ac 2 -ar 44100 - > temp1.a < /dev/null &
ffmpeg -i input2.flv -vn -f u16le -acodec pcm_s16le -ac 2 -ar 44100 - > temp2.a < /dev/null &
ffmpeg -i input1.flv -an -f yuv4mpegpipe - > temp1.v < /dev/null &
ffmpeg -i input2.flv -an -f yuv4mpegpipe - > temp2.v < /dev/null &
@{ ffmpeg -i input2.flv -an -f yuv4mpegpipe - < /dev/null | tail -n +2 > temp2.v ; @} &
cat temp1.a temp2.a > all.a &
cat temp1.v temp2.v > all.v &
ffmpeg -f u16le -acodec pcm_s16le -ac 2 -ar 44100 -i all.a \