[FFmpeg-devel] [PATCH 2/3] aacenc: Remove threshold-in-quiet modification from the 3GPP psymodel.

[Nathan Caldwell]

Removing this line vastly improves quality at a slight bitrate cost
for some samples. castanets.wav is a good example.

The closest equivalent I see to this in the 3GPP spec is a similar
modification (over a specific frequency range) when TNS is used.
---
 libavcodec/aacpsy.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/libavcodec/aacpsy.c b/libavcodec/aacpsy.c
index 5b637b8..16528d6 100644
--- a/libavcodec/aacpsy.c
+++ b/libavcodec/aacpsy.c
@@ -424,7 +424,6 @@ static void psy_3gpp_analyze(FFPsyContext *ctx, int channel,
                 band[g].thr_quiet = FFMAX(PSY_3GPP_RPEMIN*band[g].thr_quiet,
                                           FFMIN(band[g].thr_quiet,

PSY_3GPP_RPELEV*pch->prev_band[w+g].thr_quiet));
-            band[g].thr = FFMAX(band[g].thr, band[g].thr_quiet * 0.25);

             ctx->psy_bands[channel*PSY_MAX_BANDS+w+g].threshold = band[g].thr;
         }
-- 
1.7.3.2