Attachment 1969 Details for Bug 11760 – [PATCH 04] dtsdec: fix attempts to decode incomplete frames

[patch] [PATCH 04] dtsdec: fix attempts to decode incomplete frames

0004-dtsdec-fix-attempts-to-decode-incomplete-frames.patch (text/plain), 1.50 KB, created by Sergey Vlasov on 2007-05-17 13:56:01 MSD

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Creator: Sergey Vlasov

Created: 2007-05-17 13:56:01 MSD

Size: 1.50 KB

patch

obsolete

>From 50939b9fd93319abb3da2a81d93e390173dde59c Mon Sep 17 00:00:00 2001
>From: Sergey Vlasov <vsu@altlinux.ru>
>Date: Thu, 17 May 2007 09:26:35 +0400
>Subject: dtsdec: fix attempts to decode incomplete frames
>
>When (!len) is checked in the buffer fill loop in dts_decode_frame(),
>the buffer does not contain a complete frame, therefore executing
>"break" when there is no more input data is not correct (subsequent
>code will try to decode the buffer, which then will lead to garbage
>output and sync loss).  The proper action is to return the number of
>consumed bytes and wait for more data.
>
>The problematic case can be triggered by mplayer - apparently it
>passes the stream to decoder without caring about frame boundaries,
>and sometimes the data block happens to contain just the frame header;
>in this case the first pass through the loop will consume HEADER_SIZE
>bytes from the input data, and the second pass would trigger the bug.
>
>Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>
>---
> libavcodec/dtsdec.c |    2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
>diff --git a/libavcodec/dtsdec.c b/libavcodec/dtsdec.c
>index 275dccb..afe266a 100644
>--- a/libavcodec/dtsdec.c
>+++ b/libavcodec/dtsdec.c
>@@ -191,7 +191,7 @@ dts_decode_frame(AVCodecContext * avctx, void *data, int *data_size,
> 
>         len = end - start;
>         if(!len)
>-            break;
>+            return start - buff;
>         if(len > s->bufpos - s->bufptr)
>             len = s->bufpos - s->bufptr;
>         memcpy(s->bufptr, start, len);
>-- 
>1.5.1.1.197.g66b3
>

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