[FFmpeg-devel] [PATCH]Add little-endian G726 decoder and use it for Sun AU files

Paul B Mahol onemda at gmail.com
Fri Aug 2 14:30:48 CEST 2013


On 8/1/13, Michael Niedermayer <michaelni at gmx.at> wrote:
> On Thu, Aug 01, 2013 at 09:59:10PM +0000, Paul B Mahol wrote:
>> On 8/1/13, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
>> > Paul B Mahol <onemda <at> gmail.com> writes:
>> >
>> >> > whats the status of this patch & thread ?
>> >>
>> >> I already did posted patch for g726
>> >
>> > Maybe I misremember, but your patch does not
>> > work or do I miss something?
>> >
>> >> and I'm the one who originally found solution.
>> >
>> > To some degree, yes.
>> > (Roman explained it several years ago and I pointed
>> > out the German Wikipedia article iirc.)
>> >
>> >> If I did not posted patch,
>> >
>> >> also if I never commited get_bits_le
>> >
>> > If you remember correctly, I had implemented a
>> > solution before you implemented get_bits_le.
>> > (But I of course prefer the solution with
>> > get_bits_le very much.)
>>
>> Your solution was just giving noise.
>>
>> I will repeat once last time:
>>
>> Adding another codec is wrong and is hack.
>>
>
>
>> Proper solution is implementing code that
>> trys both paths and picks one with more sensible output, which I
>> already mentioned in another thread.
>
> compressing the data with DCT (vbr mp3)
> (this uses the asf file we have)
>
> -rw-r----- 1 michael michael  32040 Aug  2 00:00 le.mp3
> -rw-r----- 1 michael michael  31608 Aug  2 00:00 be.mp3
>
> the difference is just about 1% over the whole file
>
> and heres flac instead for a non dct variant
> -rw-r----- 1 michael michael 149954 Aug  1 23:45 le.ogg
> -rw-r----- 1 michael michael 149499 Aug  1 23:46 be.ogg
>
>
> also if you encode noise a fft/dct style detection will fail,
> a movie would likely  sound bad if parts that supposed to sound like
> noise get decoded with the wrong endianness
>
> also the first packets quite commonly could be totally silent and
> that maybe wont be distingishable le vs be like

That would be easy to detect.

Also what stops you muxing be variant into containers you think
are using le variant?


>
> [...]
>
> --
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> No human being will ever know the Truth, for even if they happen to say it
> by chance, they would not even known they had done so. -- Xenophanes
>


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