[FFmpeg-devel] [PATCH] avcodec: Fix duration error after seek operation

王兴超 wangxingchao at xiaomi.com
Fri Nov 15 09:14:32 CET 2013

Hi Michael/Justin,

I met a "duration set" bug in cook parser when seeking, the first audio packet always dropped as its pts/dts be AV_NOPTS_VALUE.
After some investigation, the root cause is AVCodecParserContext 's duration was forgot set after duration calculation. The attached
patch could fix this issue and i verify it with latest commit, pls feel free to let me know if there's potential issue.

From: wangxingchao [wangxingchao at xiaomi.com]
Sent: Friday, November 15, 2013 4:03 PM
To: 王兴超
Subject: [PATCH] avcodec: Fix duration error after seek operation

After seek, s->duration need recalculation, AVCodecParserContext need be set
again. Without the fix, the first audio packet would be dropped after
compute_pkt_fields() as the final pts/dts become invalid.

Signed-off-by: wangxingchao <wangxingchao at xiaomi.com>
 libavcodec/cook_parser.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/libavcodec/cook_parser.c b/libavcodec/cook_parser.c
index f17f56e..fed9419 100644
--- a/libavcodec/cook_parser.c
+++ b/libavcodec/cook_parser.c
@@ -40,11 +40,12 @@ static int cook_parse(AVCodecParserContext *s1, AVCodecContext *avctx,
     CookParseContext *s = s1->priv_data;

-    if (s->duration)
-        s1->duration = s->duration;
-    else if (avctx->extradata && avctx->extradata_size >= 8 && avctx->channels)
+    if (!s->duration &&
+               avctx->extradata && avctx->extradata_size >= 8 && avctx->channels)
         s->duration = AV_RB16(avctx->extradata + 4) / avctx->channels;

+    s1->duration = s->duration;
     /* always return the full packet. this parser isn't doing any splitting or
        combining, only setting packet duration */
     *poutbuf      = buf;
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