[FFmpeg-user] Tnascode H.264 HLS to MPEG2 UDP TS (for DVB-Cbroadcast)

[Andrey Utkin]

2013/2/27 Roman A. Tarasov <roman at barsmedia.ru>:
>>> Existing problems:
>>> 1. Random hangs (on the server with Xeon E5450 2.4Ghz loaded by
>>> 25-30%), even when reading files from a local web server
>
>>Please provide full uncut console output, with option -loglevel debug
> Check that you use recent version.
>
>
> Console out:
> frame=   80 fps= 23 q=2.5 Lsize=    1212kB time=00:00:03.16
> bitrate=3141.7kbits/s dup=29 drop=0
> video:1042kB audio:70kB subtitle:0 global headers:0kB muxing overhead
> 8.966129%
> [AVIOContext @ 0210b300] Statistics: 471 bytes read, 0 seeks
> Received signal 2: terminating.

Did you mean that it hung at this point?
If it hangs regularly during work, try attaching to the process with gdb.

>>> 2. HLS in the playlist starts to play with the predictions of the
> last
>>> movie, and not from the beginning of the playlist.
>
>>Please elaborate what you mean.
>
> In this playlist:
> #EXTM3U
> #EXT-X-VERSION:2
> #EXT-X-ALLOW-CACHE:NO
> #EXT-X-TARGETDURATION:5
> #EXT-X-MEDIA-SEQUENCE:40978
>
> #EXT-X-KEY:METHOD=NONE
>
> #EXTINF:5,
> http://127.0.0.1/stream2013_2_25_9_16_16-40978.ts
> #EXTINF:6,
> http://127.0.0.1/stream2013_2_25_9_16_21-40979.ts
> #EXTINF:6,
> http://127.0.0.1/stream2013_2_25_9_16_27-40980.ts
> #EXTINF:5,
> http://127.0.0.1/stream2013_2_25_9_16_33-40981.ts
> #EXTINF:6,
> http://127.0.0.1/stream2013_2_25_9_16_38-40982.ts
> #EXTINF:6,
> http://127.0.0.1/stream2013_2_25_9_16_44-40983.ts
> #EXTINF:6,
> http://127.0.0.1/stream2013_2_25_9_16_50-40984.ts
> #EXTINF:6,
> http://127.0.0.1/stream2013_2_25_9_16_56-40985.ts
> #EXTINF:5,
> http://127.0.0.1/stream2013_2_25_9_17_2-40986.ts
> #EXTINF:6,
> http://127.0.0.1/stream2013_2_25_9_17_7-40987.ts
>
>
> Playing started from http://127.0.0.1/stream2013_2_25_9_16_56-40985.ts,
> but no from http://127.0.0.1/stream2013_2_25_9_16_16-40978.ts

I have no idea on this.

>>> 3. Bitrate jumps from 4000 to 6000.
>
>>Maybe try x264 video encoder, it may be more flexible and developed.
>>Maybe it will control bitrate more precisely.
>>BTW -tune zerolatency is x264 encoder option, mpeg2video encoder does
> not support it.
>
> Broadcast operator need from MPEG2 from us.

OK. BTW how do you measure output bitrate? if you check realtime UDP
traffic rate, then take into consideration that video transcoding
process is not strictly linear, but somewhat bursty in meaning of
produced data rate.

-- 
Andrey Utkin