[FFmpeg-devel] [PATCH] h264/aac in flv

[RAFAEL JHONNY GOMEZ AGUILAR]

no jodannnnnnnnnnnnnnnnnnnnnnnnnnnnn> Date: Tue, 6 May 2008 20:16:02 +0200> From: michaelni at gmx.at> To: ffmpeg-devel at mplayerhq.hu> Subject: Re: [FFmpeg-devel] [PATCH] h264/aac in flv> > On Tue, May 06, 2008 at 07:31:53PM +0200, Baptiste Coudurier wrote:> > Michael Niedermayer wrote:> > >>>>>> [...]> > >>>>>> > > >>>>>> static int get_audio_flags(AVCodecContext *enc){> > >>>>>> int flags = (enc->bits_per_sample == 16) ? FLV_SAMPLESSIZE_16BIT : FLV_SAMPLESSIZE_8BIT;> > >>>>>> > > >>>>>> + if (enc->codec_id == CODEC_ID_AAC) // specs force these parameters> > >>>>>> + return FLV_CODECID_AAC | FLV_SAMPLERATE_44100HZ | FLV_SAMPLESSIZE_16BIT | FLV_STEREO;> > >>>>> Is this also correct for AAC streams for which these arent true? Or are> > >>>>> such streams just not supported?> > >>>>>> > >>>> Streams are supported (like mp3 48khz btw), and play well. Like written,> > >>>> specs mandates these values.> > >>> I know but what about lets say 48khz AAC or 22khz AAC your code would mux this> > >>> with a claimed samplerate of 44khz.> > >>> Is such 22khz AAC and 48khz AAC legal in flv accoridng to spec or is just> > >>> 44khz AAC allowed?> > >>> If later then the muxer should reject AAC with samplerates differing from > > >>> 44khz.> > >>>> > >> Rofl:> > >> "Sampling rate> > >> For AAC: always 3"> > >>> > >> Is this ok for you ?> > > > > > Ive not doubted that this has to be set to 3. The question is if> > > 48khz/22khz AAC is allowed in flv or not. If one takes the spec literally> > > then the awnser is clearly no.> > > > Well, I would say it is probably yes, considering aac and> > AudioSpecificConfig.> > > > > But your muxer would store them blindly> > > with a claimed sample rate of 44khz.> > > > Well, what can I say ? It's not clearly mentioned.> > I fear they used the same crap as mp4, AudioSpecificConfig mentions the> > correct sample rate and channels number.> > This is the case for channels too:> > > > "SoundType UB[1]> > 0 = sndMono> > 1 = sndStereo> > Mono or stereo sound> > For Nellymoser: always 0> > For AAC: always 1"> > > > Im in favor of muxing this way.> > Iam ok with that if the official software also generates such 22/48khz AAC.> > [...]> > -- > Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB> > The misfortune of the wise is better than the prosperity of the fool.> -- Epicurus
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