[SCM] libav/experimental: Fix for a problem with inverted sign of output data from ffvorbis decoder.

[siretart at users.alioth.debian.org]

The following commit has been merged in the experimental branch:
commit 7dfed8e1dce97a45f501ddedbdd69f30f09f0468
Author: Siarhei Siamashka <siarhei.siamashka at gmail.com>
Date:   Wed May 20 07:24:38 2009 +0000

    Fix for a problem with inverted sign of output data from ffvorbis decoder.
    
    Now the sign of audio samples in ffvorbis output is the same as in original
    uncompressed audio file and this also allows the use of tiny_psnr to compare
    ffvorbis with libvorbis/tremor.
    
    Originally committed as revision 18878 to svn://svn.ffmpeg.org/ffmpeg/trunk

diff --git a/libavcodec/vorbis_dec.c b/libavcodec/vorbis_dec.c
index f7b10e6..827619e 100644
--- a/libavcodec/vorbis_dec.c
+++ b/libavcodec/vorbis_dec.c
@@ -896,8 +896,8 @@ static int vorbis_parse_id_hdr(vorbis_context *vc){
     vc->saved           = av_mallocz((vc->blocksize[1]/4)*vc->audio_channels * sizeof(float));
     vc->previous_window=0;
 
-    ff_mdct_init(&vc->mdct[0], bl0, 1, 1.0);
-    ff_mdct_init(&vc->mdct[1], bl1, 1, 1.0);
+    ff_mdct_init(&vc->mdct[0], bl0, 1, -1.0);
+    ff_mdct_init(&vc->mdct[1], bl1, 1, -1.0);
 
     AV_DEBUG(" vorbis version %d \n audio_channels %d \n audio_samplerate %d \n bitrate_max %d \n bitrate_nom %d \n bitrate_min %d \n blk_0 %d blk_1 %d \n ",
             vc->version, vc->audio_channels, vc->audio_samplerate, vc->bitrate_maximum, vc->bitrate_nominal, vc->bitrate_minimum, vc->blocksize[0], vc->blocksize[1]);

-- 
Libav/FFmpeg packaging