[FFmpeg-devel] [PATCH] Fix amrnb decoder scaling

[Martin Storsjö]

On Sun, 2 May 2010, Ronald S. Bultje wrote:

> On Sun, May 2, 2010 at 5:24 PM, Martin Storsj? <martin at martin.st> wrote:
> > On Sun, 2 May 2010, Ronald S. Bultje wrote:
> >> On May 2, 2010, at 4:33 PM, Benjamin Larsson <banan at ludd.ltu.se> wrote:
> >> > On 02/05/10 22:31, Martin Storsj? wrote:
> >> >>
> >> >> The output from the amrnb decoder is currently broken, since rev
> >> >> 22937. In
> >> >> that commit, this chunk removed both scaling and clipping, even if
> >> >> only
> >> >> clipping was intended to be removed:
> >> >>
> >> >> @@ -1048,10 +1046,6 @@ static int amrnb_decode_frame(AVCodecContext
> >> >> *avctx, void *data, int *data_size
> >> >> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? highpass_poles,
> >> >> highpass_gain,
> >> >> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? p->high_pass_mem,
> >> >> AMR_BLOCK_SIZE);
> >> >>
> >> >> - ? ?for (i = 0; i< ?AMR_BLOCK_SIZE; i++)
> >> >> - ? ? ? ?buf_out[i] = av_clipf(buf_out[i] * AMR_SAMPLE_SCALE,
> >> >> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?-1.0, 32767.0 / 32768.0);
> >> >
> >> > I'm quite sure the scaling can be added to some other step, so the
> >> > loop wouldn't be needed.
> >>
> >> Yes, multiply it with highpass_gain in the function call before.
> >
> > Thanks! Yes, that works just as well, see the attached.
> 
> Patch OK, I think.

Applied

// Martin