[FFmpeg-devel] [PATCH 2/5] libmp3lame + mp3enc: removes decoder delay compensation

[Jon Toohill]

initial_padding specifies only encoder delay, decoder delay is
handled by start_skip_samples.
---
 doc/APIchanges          | 4 ++++
 libavcodec/libmp3lame.c | 2 +-
 libavcodec/version.h    | 2 +-
 libavformat/mp3enc.c    | 4 ++--
 4 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/doc/APIchanges b/doc/APIchanges
index d777dc0..ae450e1 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -15,6 +15,10 @@ libavutil:     2015-08-28
 
 API changes, most recent first:
 
+2016-07-12 - xxxxxxx - lavc 57.47.100 - libmp3lame.c
+  Removed MP3 decoder delay from initial_padding in AVCodecContext.
+  initial_padding only includes the encoder delay.
+
 2016-04-27 - xxxxxxx - lavu 55.23.100 - log.h
   Add a new function av_log_format_line2() which returns number of bytes
   written to the target buffer.
diff --git a/libavcodec/libmp3lame.c b/libavcodec/libmp3lame.c
index 5642264..198ac94 100644
--- a/libavcodec/libmp3lame.c
+++ b/libavcodec/libmp3lame.c
@@ -137,7 +137,7 @@ static av_cold int mp3lame_encode_init(AVCodecContext *avctx)
     }
 
     /* get encoder delay */
-    avctx->initial_padding = lame_get_encoder_delay(s->gfp) + 528 + 1;
+    avctx->initial_padding = lame_get_encoder_delay(s->gfp);
     ff_af_queue_init(avctx, &s->afq);
 
     avctx->frame_size  = lame_get_framesize(s->gfp);
diff --git a/libavcodec/version.h b/libavcodec/version.h
index 0852b43..37a6e17 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -28,7 +28,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVCODEC_VERSION_MAJOR  57
-#define LIBAVCODEC_VERSION_MINOR  46
+#define LIBAVCODEC_VERSION_MINOR  47
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
diff --git a/libavformat/mp3enc.c b/libavformat/mp3enc.c
index de63401..3b77d29 100644
--- a/libavformat/mp3enc.c
+++ b/libavformat/mp3enc.c
@@ -249,10 +249,10 @@ static int mp3_write_xing(AVFormatContext *s)
     avio_w8(dyn_ctx, 0);      // unknown abr/minimal bitrate
 
     // encoder delay
-    if (par->initial_padding - 528 - 1 >= 1 << 12) {
+    if (par->initial_padding >= 1 << 12) {
         av_log(s, AV_LOG_WARNING, "Too many samples of initial padding.\n");
     }
-    avio_wb24(dyn_ctx, FFMAX(par->initial_padding - 528 - 1, 0)<<12);
+    avio_wb24(dyn_ctx, par->initial_padding << 12);
 
     avio_w8(dyn_ctx,   0); // misc
     avio_w8(dyn_ctx,   0); // mp3gain
-- 
2.8.0.rc3.226.g39d4020