[FFmpeg-devel] [PATCH] Speex decoding via libspeex

Michael Niedermayer michaelni
Thu Oct 23 14:32:19 CEST 2008

On Tue, Oct 21, 2008 at 11:17:48PM -0400, David Conrad wrote:
> On Oct 21, 2008, at 3:17 PM, Art Clarke wrote:
>> On Mon, Oct 20, 2008 at 11:45 PM, David Conrad <lessen42 at gmail.com> wrote:
>>> On Oct 21, 2008, at 2:36 AM, Diego Biurrun wrote:
>>>> On Tue, Oct 21, 2008 at 02:30:01AM -0400, David Conrad wrote:
>>>>> This adds decode support for Speex using libspeex. Tested with
>>>>> talk109-
>>>>> q5.spx and speexaudio.flv
>>>>> I'm not sure the best way to handle Speex in flv;
>>>> Since when does Speex exist in flv?  Isn't Ogg the preferred
>>>> container?
>>> Since Flash 10 just recently came out; I'd say see issue 605 if
>>> roundup wasn't down.
>>>> Build system part of the patch is OK.
>>>> Diego
>> Hi David,
>> It looks like (from the investigation we've done on Red5) that Adobe
>> always passed 16khz audio in the FLV under Flash Player 10.  It sends
>> a audio-rate ID of "0" in that case, so you're save hardcoding
>> avctx->sample_rate to 16000 if the codec is speex.  That should fix
>> the ffmpeg -i problem.
>> Patch attached.
>> See here for background:
>> http://jira.red5.org/confluence/display/codecs/Speex+Codec
> It looks like the sample rate is now the only real issue with decoding 
> Speex without a setup header, assuming the default mode is used for a given 
> sample rate. I've reworked the decoding loop to not rely on knowing 
> frames_per_packet so that issue is irrelevant with flv.
> Also, stereo speex is now supported. As a side note, libspeex 1.0.5 can 
> encode stereo fine but completely fails at decoding it.

patch looks ok

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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