[FFmpeg-devel] [RFC][PATCH] return packets for known codecs earlier when codec probing is done

[Baptiste Coudurier]

On 5/27/2009 3:00 PM, Michael Niedermayer wrote:
> On Wed, May 27, 2009 at 12:54:27AM -0700, Baptiste Coudurier wrote:
>> Hi Michael,
>>
>> Michael Niedermayer wrote:
>>> [...]
>>>
>>>> @@ -537,10 +537,18 @@ int av_read_packet(AVFormatContext *s, AVPacket *p
>>>>  
>>>>          av_init_packet(pkt);
>>>>          ret= s->iformat->read_packet(s, pkt);
>>>> -        if (ret < 0)
>>>> -            return ret;
>>>> +        if (ret < 0) {
>>>> +            if (!pktl)
>>>> +                return ret;
>>>> +            for (i = 0; i < s->nb_streams; i++)
>>>> +                if (s->streams[i]->codec->codec_id == CODEC_ID_PROBE)
>>>> +                    s->streams[i]->codec->codec_id = CODEC_ID_NONE;
>>>> +            continue;
>>>> +        }
>>> i dont like this
>>>
>> Well, we have a problem if probe_packets is not 0 when eof is reached.
>> Do you see another way to avoid this ?
> 
> is this special case really relevant?
> it just looses data on streams when all of the following is true
> * stream is set to CODEC_ID_PROBE
> * stream contains less than 100 packets in the whole file
> * probing fails even with all packets in the whole file

I think it is:
code will call av_read_packet until st->probe_packets is 0, which will
provoke an infinite loop.

We have to stop in some way. EOF means, CODEC_ID_PROBE is now CODEC_ID_NONE.

> besides the code also breaks EAGAIN i think

Yes, I think you are right, I'll fix it.

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
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