On 12/4/2017 4:39 AM, Rostislav Pehlivanov wrote:
> On 2 December 2017 at 17:46, Andrew D'Addesio <modchip...@gmail.com> wrote:
>
>> When decoding to downmixed mono, don't put the channels out of phase,
>> as they will cancel out and create audible artifacts. (See
>> RFC 8251 sec. 10.)
>>
>> Signed-off-by: Andrew D'Addesio <modchip...@gmail.com>
>> ---
>> libavcodec/opus_pvq.c | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> diff --git a/libavcodec/opus_pvq.c b/libavcodec/opus_pvq.c
>> index 2f7aa74..f18c010 100644
>> --- a/libavcodec/opus_pvq.c
>> +++ b/libavcodec/opus_pvq.c
>> @@ -643,7 +643,13 @@ static av_always_inline uint32_t
>> quant_band_template(CeltPVQ *pvq, CeltFrame *f,
>> }
>> } else {
>> inv = (b > 2 << 3 && f->remaining2 > 2 << 3) ?
>> ff_opus_rc_dec_log(rc, 2) : 0;
>> +
>> + /* Don't put the channels out of phase if we are decoding
>> to downmixed
>> + * mono as this subjectively sounds bad (RFC 8251 section
>> 10). */
>> + if (f->channels == 1)
>> + inv = 0;
>> }
>> +
>> itheta = 0;
>> }
>> qalloc = opus_rc_tell_frac(rc) - tell;
>> --
>> 2.15.1.windows.2
>>
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel@ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>
>
> RFC8251 made this optional, pushed a new version which added an option to
> toggle this.
Valgrind complains about your changes in 1b8649c2ce. Conditional jump or
move depends on uninitialised value(s).
http://fate.ffmpeg.org/report.cgi?time=20171204200723&slot=x86_64-archlinux-gcc-valgrind
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