John Van Sickle <[email protected]> added the comment:
Patch attached with working method.
____________________________________________________
FFmpeg issue tracker <[email protected]>
<https://roundup.ffmpeg.org/roundup/ffmpeg/issue269>
____________________________________________________
--- faq.texi 2009-12-08 20:32:01.722184156 -0500
+++ faq.texi 2010-01-06 01:28:09.242282703 -0500
@@ -316,6 +316,11 @@ ffmpeg -f mpeg -i - -sameq -vcodec mpeg4
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, @co...@{ ;@}}, 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 \
