[opus] High noise after encoding/decoding procedure

Ralph Giles giles at thaumas.net
Thu Jul 14 14:18:55 UTC 2016

Glad you got it working.
 - r

On July 14, 2016 5:00:39 AM PDT, Aleksandr Mikoff <sir.enmity at gmail.com> wrote:
>Thanks a lot for your tips.
>What I have to done to debug: got the raw wav-file,
>it on my PC and saved OPUS packets as an array. Moved this array to the
>embedded platform and made sure that the frames decoded from the OPUS
>packets are the same. However, the high noise level was the same, but
>wasn`t caused by OPUS.
>The problem was with my sound bus between an embedded device and the
>speaker - there was an one bit offset between FS signal and sound
>which I didn't take into account. Now I have the clear enough sound
>30% MCU load for full duplex sound.
>2016-07-12 20:46 GMT+03:00 Ralph Giles <giles at thaumas.net>:
>> On 2016-07-12 9:34 AM, Aleksandr Mikoff wrote:
>> > If I encode each frame, decode it and send it back to the speakers
>> > hear a very noisy signal - it is so large, so it is almost
>impossible to
>> > distinguish words in my speech...
>> This effect can be caused by some data type issues:
>>  - If you are using opus_encode() and opus_decode(), make sure to use
>> 16-bit signed integer samples in the pcm buffer. If you have 8-bit
>> samples you'll have to convert them.
>>  - Make sure you're passing the length of the pcm buffer in _samples_
>> not _bytes_.
>>  - Make sure you're passing the size of the compressed opus data in
>> _bytes_.
>> > Is it ok, that I changed few parameters in "defines.h" file (to
>> > suppress the RAM requirements - I have only 60 KB RAM free on my
>> > board)? I changed the ENCODER_NUM_CHANNELS 1 and
>> > one, and MAX_FS_KHZ to 8.
>> That's not a tested configuration, so it's possible this broke
>> something. If you make the same changes and build for a desktop
>> does audio round-trip through opus_demo correctly?
>>  -r
>> _______________________________________________
>> opus mailing list
>> opus at xiph.org
>> http://lists.xiph.org/mailman/listinfo/opus
>С уважением,
>Миков Александр
>IMU based localization:
>RTL-Service (RealTrac) won EvAAL competition:
>RealTrac video presentation (in Russian):
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