[FFmpeg-devel] [PATCH] DCA-in-WAV detection

Måns Rullgård mans
Fri May 4 15:15:42 CEST 2007


Kostya wrote:
> On Fri, May 04, 2007 at 11:50:37AM +0200, Michael Niedermayer wrote:
>> Hi
>>
>> On Fri, May 04, 2007 at 09:30:27AM +0100, M?ns Rullg?rd wrote:
>> > Kostya <kostya.shishkov at gmail.com> writes:
>> >
>> > > Here is my attempt on patch discussed on Febryary 2006
>> > > Thread called "[PATCH] Fix DTS in WAV file playback."
>> >
>> > Wouldn't it be simpler to call av_probe_input_format or so on some
>> > data from the start of the data section of the file?  That would also
>> > take care of AC3 in WAV masquerading as PCM.
>>
>> Note, also see av_find_stream_info() code releated to codec_identified
>
> I suppose that this is only WAV related and should be treated there.
> Also it is gladly is not the common practice so I think checking for
> those two formats is enough. While I haven't seen AC3 in WAV, DTS in WAV
> seems to be a common practice (but still a hack).

I have seen AC3 in WAV done that way.  There is a simple explanation for
this ugly practice.  Labeling the data as PCM allows one to use stupid CD-R
software to burn the data as an audio track which can then be played back
through a hardware DTS/AC3 decoder.  It's not what I call an acceptable
explanation, but it is an explanation nonetheless.

-- 
M?ns Rullg?rd
mans at mansr.com




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