[FFmpeg-devel] H264: mp4toannexb BSF and streaming

Alexandre Ferrieux alexandre.ferrieux
Wed Aug 18 15:45:54 CEST 2010


On 18/08/2010 14:59, Benjamin Larsson wrote:
> On 08/18/2010 02:42 PM, Alexandre Ferrieux wrote:
>> Hi,
>>
>> [...]
>>
>> I would like to transcode it on-the-fly without waiting for the full
>> 3GP file to be received. I know that the 3GP format is not AT ALL
>> designed for that, and that even the first chunks will be invalid
>> since the 3GP-writer application does a seek() back to the beginning
>> to fill the header, etc. In short, 3GP is utterly non-streamable, but
>> I need to do something with it nevertheless :/
>
> Not true, ahs exists.
>
> http://ftp.3gpp.org/specs/html-info/26234.htm
>
> Chapter 12 of latests spec.

Thanks, but the existence of smarter uses of the format doesn't help me for existing dumb uses (like the Android 3GP 
writer). Just found in mov.c:

       /* .mov and .mp4 aren't streamable anyway (only progressive download if moov is before mdat) */

so it looks like this "dumb use" is pretty ubiquitous. Sigh.

-Alex




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