[Ffmpeg-devel] [PATCH] Re: AMR bitrate

[Martin]

Hi,

Martin wrote:
> Hi,
> 
> Benjamin Larsson wrote:
> 
>>Martin skrev:
>>
>>
>>>Hi,
>>>
>>>gravsten at yahoo.com wrote:
>>>
>>>
>>>>>>I have a question regarding encoding and decoding of AMR using
>>>>>>ffmpeg. To me it seems that the bitrate mode is fixed after
>>>>>>avcodec_open(). Is that correct (the bitrate mode cannot be changed
>>>>>>on the fly)?
>>>>>
>>>>>No the bitrate can't be changed on the fly and user questions
>>>>>to the user list.
>>>>
>>>>
>>>>Actually, the standard let one negotiation a set of AMR bit rates
>>>>beforehand,
>>>>and the transmitter may arbitrarily change bitrate within the agreed
>>>>set on an
>>>>AMR frame boundary (20ms).
>>>>
>>>>I am unsure whether ffmpeg let you change the bitrate on-the-fly
>>>>(i.e. without
>>>>close/open codec), but if not, you should be able to fix this by
>>>>merely making
>>>>the AMR codec access a bitrate value in the avctx structure directly
>>>>(ffmpeg
>>>>only serves as a proxy to an external AMR library originally from the
>>>>ITU).
>>>
>>>
>>>thanks for clarifying that!
>>>I tested it and it worked. Would you accept a patch for that? There
>>>shouldn't be a downside in directly accessing the avctx structure, right?
>>>
>>>Martin
>>
>>
>>Send the patch for review.
> 

I attached a patch for amr bitrate mode which can now be changed "on the
fly" through avctx->bitrate. Is the attached patch ok? I have sent it a
week ago but I have no reply whether it is ok and will be applied.

Martin
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