[FFmpeg-devel] Implementation of Huffman codes for DCA encoder

[Даниил Чередник]

With real music and 256k bitrate encoding (the source was 44100, 16bit
stereo) I got:
Without Huffman: Best PSNR is  31.77 for shift 0
With: Best PSNR is  37.45 for shift 0

Current implementation of DCA encoder has minimal set of DTS features (no
ADPCM, no VQ, fixed amount of transmitted subbands, no transient control,
etc). So distortion is quite audible. Current set of patches introduces
Huffman encoding for quantized audio data which is equivalent of increasing
bitrate for 10-20%. Also bitstream allows to use Huffman for scale factor
indexes, and some other data. I am working on it too.

I have attached new split set of patches.

On Sat, Jan 7, 2017 at 11:50 PM, Carl Eugen Hoyos <ceffmpeg at gmail.com>
wrote:

> 2017-01-07 20:39 GMT+01:00 Rostislav Pehlivanov <atomnuker at gmail.com>:
> > On 7 January 2017 at 16:11, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
> >
> >> 2017-01-07 16:00 GMT+01:00 Даниил Чередник <dan.cherednik at gmail.com>:
> >>
> >> > Currently I am working on improvement quality of DTS encoder.
> Following
> >> > patches introduce Huffman coding.
> >>
> >> Is the quality improvement so obvious that no further tests are
> necessary?
> >> (Does psnr improve measurably?)
> >>
> > PSNR is pretty much useless for audio.
>
> > The ear's the only metric which works.
>
> Not everybody's;-))
>
> > From the 2 samples he posted I can tell there's a big difference, and the
> > encoder isn't very good right now and the patch definitely helps.
>
> Thank you!
>
> Carl Eugen
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>



-- 
Daniil Cherednik
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