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

[Rostislav Pehlivanov]

On 15 January 2017 at 15:14, Даниил Чередник <dan.cherednik at gmail.com>
wrote:

> Hi.
> Is there any issue in this patch?
>
> On Sun, Jan 8, 2017 at 1:22 AM, Даниил Чередник <dan.cherednik at gmail.com>
> wrote:
>
> > 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
> >> _______________________________________________
> >> ffmpeg-devel mailing list
> >> ffmpeg-devel at ffmpeg.org
> >> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >>
> >
> >
> >
> > --
> > Daniil Cherednik
> >
>
>
>
> --
> Daniil Cherednik
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>

Thanks, pushed