[FFmpeg-devel] DVB Subtitles

JULIAN GARDNER joolzg at btinternet.com
Sun Jun 10 15:55:17 CEST 2012

> From: Michael Niedermayer <michaelni at gmx.at>
>To: FFmpeg development discussions and patches <ffmpeg-devel at ffmpeg.org> 
>Sent: Sunday, 10 June 2012, 15:17
>Subject: Re: [FFmpeg-devel] DVB Subtitles
>On Sun, Jun 10, 2012 at 01:12:11PM +0100, JULIAN GARDNER wrote:
>> Just pulled a new build and started trying my test dvb subtitles streams and NONE work, get loads of errors about DTS being wrong on the subtitle stream.
>> Is there ongoing work to fix these or is dvb subtitles being left for dead?
>> I did read a bit about the timeout, and someone saying that they are never about 20 seconds, well from my work i have seen dvb subs used to put a small channel icon on screen, and was present for nearly 2 hours.
>Some "subtitles" may be present for 2 hours but the packets likely
>get repeated at intervals shorter than 20 seconds otherwise one could
>not start playback of such a stream from the middle. And i find even
>20seconds unlikely long for that. That would implicate if one tuned
>to a channel and started watching the channel logo would be missing
>for 20 seconds in some cases

hmm does not matter Micheal as long as the epoch does not change and the end_time is correct every packet will say Start at 0 end at 120, if you join in the middle you will still get the 1st epoch and as your in the stream you will show it until 2 hours from the start.

>> Also the timeout sent is used as a "get out of jail", for removal in case of corrupted streams.
>> Should i look into fixing it again, and if so what has been done to the chain as the last time i fixed it, and added hard subtitles, i used the deinterlace funstion to add hard subtitles to the output.
>maybe nicolas and ubitux could comment here

To be honest, Ill just fix ffmpeg again, removing incorrect stuff like saying DVBSUBS needs 2 packets to turn on/off, and i will fix the decoder to do epochs again as well as fix the buffer overruns in the enocder.

If anyone wants them i will pass them on.


More information about the ffmpeg-devel mailing list