From 2f6fc566ccaab90a089758155f5dfdd7bfb6d519 Mon Sep 17 00:00:00 2001
From: nu774 <honeycomb77@gmail.com>
Date: Sun, 20 Oct 2013 21:33:06 +0900
Subject: [PATCH] improve handling of avgBitrate

---
 src/m4af.c | 13 ++++++++-----
 src/m4af.h |  2 ++
 src/main.c |  1 +
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/m4af.c b/src/m4af.c
index 11650f3..931d5fe 100644
--- a/src/m4af.c
+++ b/src/m4af.c
@@ -53,6 +53,7 @@ typedef struct m4af_track_t {
     uint32_t bufferSizeDB;
     uint32_t maxBitrate;
     uint32_t avgBitrate;
+    int is_vbr;
 
     m4af_sample_entry_t *sample_table;
     uint32_t num_samples;
@@ -278,6 +279,12 @@ DONE:
     return ctx->last_error;
 }
 
+void m4af_set_vbr_mode(m4af_ctx_t *ctx, uint32_t track_idx, int is_vbr)
+{
+    m4af_track_t *track = &ctx->track[track_idx];
+    track->is_vbr = is_vbr;
+}
+
 void m4af_set_priming(m4af_ctx_t *ctx, uint32_t track_idx,
                       uint32_t encoder_delay, uint32_t padding)
 {
@@ -771,11 +778,7 @@ void m4af_write_esds_box(m4af_ctx_t *ctx, uint32_t track_idx)
                , 2);
     m4af_write24(ctx, track->bufferSizeDB);
     m4af_write32(ctx, track->maxBitrate);
-#if 0
-    m4af_write32(ctx, track->avgBitrate);
-#else
-    m4af_write32(ctx, 0);
-#endif
+    m4af_write32(ctx, track->is_vbr ? 0: track->avgBitrate);
     /* DecoderSpecificInfo */
     m4af_write_descriptor(ctx, 5, track->decSpecificInfoSize);
     m4af_write(ctx, track->decSpecificInfo, track->decSpecificInfoSize);
diff --git a/src/m4af.h b/src/m4af.h
index 7a709ec..b1d84bb 100644
--- a/src/m4af.h
+++ b/src/m4af.h
@@ -97,6 +97,8 @@ int m4af_write_sample(m4af_ctx_t *ctx, uint32_t track_idx, const void *data,
 int m4af_set_decoder_specific_info(m4af_ctx_t *ctx, uint32_t track_idx,
                                    uint8_t *data, uint32_t size);
 
+void m4af_set_vbr_mode(m4af_ctx_t *ctx, uint32_t track_idx, int is_vbr);
+
 void m4af_set_priming(m4af_ctx_t *ctx, uint32_t track_idx,
                       uint32_t encoder_delay, uint32_t padding);
 
diff --git a/src/main.c b/src/main.c
index 216a479..eca3a9c 100644
--- a/src/main.c
+++ b/src/main.c
@@ -738,6 +738,7 @@ int main(int argc, char **argv)
                                        aacinfo.confSize);
         m4af_set_fixed_frame_duration(m4af, 0,
                                       framelen >> downsampled_timescale);
+        m4af_set_vbr_mode(m4af, 0, params.bitrate_mode);
         m4af_set_priming_mode(m4af, params.gapless_mode + 1);
         m4af_begin_write(m4af);
     }
-- 
2.30.2