Re: GstVolume with dizzy is not working when changing to a value inferior to 1

[Carlos Rafael Giani <dv@pseudoterminal.org>]

On 03/03/2015 01:20 PM, Otavio Salvador wrote:
> Hello Stephane,
>
> On Tue, Mar 3, 2015 at 7:13 AM, scerveau <scerveau@gmail.com> wrote:
>> Dear all,
>>
>> I'm facing an issue with dizzy on imx6q and gstreamer 1.4.1. The volume
>> element is not working properly.
>> Whith this pipeline:
>>
>> gst-launch-1.0 audiotestsrc ! volume volume=0.5 ! alsasink
>>
>> The sound level is equal to 0 instead of half of the standard volume. If i
>> put volume=1 this is working properly.
>> Affter investigation i understood that it is related to this line
>>
>> gstvolume.c:251 self->current_volume = volume; in volume_update_volume
>>
>> If i put any log just after this line, the behaviour is coming back to
>> normal. If i compile with -00 its also working fine.
>>
>> CFLAGS += " -O0"
>>
>> That's my fix for now ;)
>>
>> Please advise on how to fix this issue because i dont know if its related to
>> the compiler (4.9.1) or to gstreamer.
> Added Khem in Cc. Khem how we can gather info to see what's going on?
>

I saw this before. It is a strange error. I did a hexdump of the input 
and output samples to see what's going on. Input samples are nonzero, as 
expected. Output samples however, are all nullbytes. Sample rate, number 
of channels, sample format are all irrelevant - it occurs with them all.

This could be a compiler bug, an error in Orc, or both, especially since 
-O0 fixes it.

Carlos