[FFmpeg-devel] Ticket4753 question

[Paul B Mahol]

On 8/7/15, Ganesh Ajjanagadde <gajjanag at mit.edu> wrote:
> On Fri, Aug 7, 2015 at 11:59 AM, Paul B Mahol <onemda at gmail.com> wrote:
>> On 8/7/15, Ganesh Ajjanagadde <gajjanag at mit.edu> wrote:
>>> https://trac.ffmpeg.org/ticket/4753:
>>> The issue seems to come from the fact that there are multiple frames per
>>> packet.
>>> In fact, the duration field of the packet is set incorrectly,
>>> and reports the duration of a single frame only (80).
>>> Unfortunately, I do not know about where/how this needs to be done,
>>> but can do this if a dev outlines the process.
>>
>> Write trivial g729_parser which splits input into 8 byte packets.
>
> Thanks, I have implemented the 8 byte case.
>
>>
>> Problem is how to tell parser from demuxer that another non 8 byte
>> mode is in operation.
>> Because decoder operates in one of two modes, either 8 byte or 10 byte.
>
> This is tricky. A dirty but simple solution would be to add a field to
> the priv_data of the avctx,
> i.e to G729Context to represent the format, and use that in the parser.
> I have not seen any other parser do this though.
>
> Note that the parser is quite limited in what it can see:
> the AVCodecParserContext can't contain this information as far as I can
> tell,
> so only AVCodecContext can.
> In this case I don't know how to do this without resorting to the priv_data.

At decoder level you can not guess it, neither at demuxer level and
AFAIK only wav does
put multiple frames into single packet. The only way is via option but
AFAIK you can not read decoder options from parser.

>
> Any suggestions?
>
>>
>>>
>>> Thanks,
>>> Ganesh
>>> _______________________________________________
>>> ffmpeg-devel mailing list
>>> ffmpeg-devel at ffmpeg.org
>>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>>
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel at ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>