[FFmpeg-user] segmenter creates empty m3u8 file

[Stefano Sabatini]

On date Tuesday 2012-06-19 07:51:35 +0100, Christian Ebert encoded:
> * Hector Cano on Monday, June 18, 2012 at 17:35:49 +0200
> > On Mon, Jun 18, 2012 at 5:01 PM, Christian Ebert <blacktrash at gmx.net> wrote:
> >> -segment_list_size triggers some content to be written to the
> >> test.m3u8 file - not very useful though, basically the same as
> >> $ ls -1 *.ts > test.m3u8
> >> But the manual says so, so I guess I cannot complain, and have to
> >> look for a "real" segmenter, or experiment with creating an m3u8
> >> myself.
> > 
> > Have you tried including the desired segment length?
> > 
> > -segment_time 10
> > 
> > That should produce 10 second long segments, as far as I have tested.
> 

> I thought so as well, but at least from my mp4 test file it does
> not make any difference - varying segment lengths from ~ 3.1 secs
> to 19.46 secs.

Segment lenght depends on the key-frames present in the file to be
fragmented, that is each fragment must start with a key-frame so the
segmenter may not honour the specified size in case there are not
"enough" key frames in the source file.

You can use -force_key_frames to force frames at a given position when 
transcoding.

I extended the segmenter, you may have a look at the following link,
create a ticket if you want to track the branch integration:
http://gitorious.org/~saste/ffmpeg/sastes-ffmpeg/commits/misc-segment-fixes-20120206
-- 
ffmpeg-user random tip #10
One minute of audio noise with ffmpeg:
ffmpeg -ar 48000 -t 60 -f s16le -acodec pcm_s16le -i /dev/urandom  \
    -ab 64K -f mp2 -acodec mp2 -y noise.mp2