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

[Paul B Mahol]

On 1/15/17, Daniil CHerednik <dan.cherednik at gmail.com> wrote:
> Hi.
> Is there any issue in this patch?

Do you plan to work more on this encoder?

Please do not top post.

>
> On Sun, Jan 8, 2017 at 1:22 AM, Daniil CHerednik <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 Daniil CHerednik <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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>>> ffmpeg-devel at ffmpeg.org
>>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>>
>>
>>
>>
>> --
>> Daniil Cherednik
>>
>
>
>
> --
> Daniil Cherednik
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