[FFmpeg-cvslog] mp3enc: Try to use a matching bitrate in the xing header.
Michael Niedermayer
git at videolan.org
Mon Nov 14 21:31:32 CET 2011
ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Mon Nov 14 20:57:30 2011 +0100| [40176fc3149bc72c1309f93989a57aec2322e626] | committer: Michael Niedermayer
mp3enc: Try to use a matching bitrate in the xing header.
Might Fix Ticket431
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=40176fc3149bc72c1309f93989a57aec2322e626
---
libavformat/mp3enc.c | 16 ++++++++++++++--
1 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/libavformat/mp3enc.c b/libavformat/mp3enc.c
index 3f2f02b..1200d0f 100644
--- a/libavformat/mp3enc.c
+++ b/libavformat/mp3enc.c
@@ -156,7 +156,9 @@ static int mp3_write_xing(AVFormatContext *s)
{
AVCodecContext *codec = s->streams[0]->codec;
MP3Context *mp3 = s->priv_data;
- int bitrate_idx = 3;
+ int bitrate_idx;
+ int best_bitrate_idx;
+ int best_bitrate_error= INT_MAX;
int64_t xing_offset;
int32_t mask, header;
MPADecodeHeader c;
@@ -185,7 +187,17 @@ static int mp3_write_xing(AVFormatContext *s)
header |= (srate_idx << 2) << 8;
header |= channels << 6;
- for (;; bitrate_idx++) {
+ for (bitrate_idx=1; bitrate_idx<15; bitrate_idx++) {
+ int error;
+ avpriv_mpegaudio_decode_header(&c, header | (bitrate_idx << (4+8)));
+ error= FFABS(c.bit_rate - codec->bit_rate);
+ if(error < best_bitrate_error){
+ best_bitrate_error= error;
+ best_bitrate_idx = bitrate_idx;
+ }
+ }
+
+ for (bitrate_idx= best_bitrate_idx;; bitrate_idx++) {
if (15 == bitrate_idx)
return -1;
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