2018-06-23 14:43 GMT+02:00, Michael Niedermayer <mich...@niedermayer.cc>:
> On Thu, Jun 21, 2018 at 10:09:14PM +0000, Carl Eugen Hoyos wrote:
>> ffmpeg | branch: master | Carl Eugen Hoyos <ceffm...@gmail.com> | Fri Jun
>> 22 00:08:13 2018 +0200| [40b7e6071815fc416a4efc5dc1616f5460a3aacb] |
>> committer: Carl Eugen Hoyos
>>
>> lavf/amr: Make the heuristic for auto-detection even stricter.
>>
>> Fixes ticket #7270.
>>
>> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=40b7e6071815fc416a4efc5dc1616f5460a3aacb
>> ---
>>
>> libavformat/amr.c | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/libavformat/amr.c b/libavformat/amr.c
>> index f954803d46..6cc06bceac 100644
>> --- a/libavformat/amr.c
>> +++ b/libavformat/amr.c
>> @@ -201,7 +201,7 @@ static int amrnb_probe(AVProbeData *p)
>> i++;
>> }
>> }
>> - if (valid > 100 && valid > invalid)
>> + if (valid > 100 && valid >> 4 > invalid)
>> return AVPROBE_SCORE_EXTENSION / 2 + 1;
>> return 0;
>> }
>> @@ -258,8 +258,8 @@ static int amrwb_probe(AVProbeData *p)
>> i++;
>> }
>> }
>> - if (valid > 100 && valid > invalid)
>> - return AVPROBE_SCORE_EXTENSION / 2 - 1;
>> + if (valid > 100 && valid >> 4 > invalid)
>> + return AVPROBE_SCORE_EXTENSION / 2 + 1;
>
> This breaks detecting the h263 file:
>
> https://samples.ffmpeg.org/V-codecs/h263/h263-raw/messenger.h263
Attached patch fixes the existing heuristic to avoid detection of files
like this one.
Sorry, Carl Eugen
From 3bfac3c9a525e8ce92c025ee2853a600d71e64d5 Mon Sep 17 00:00:00 2001
From: Carl Eugen Hoyos <ceffm...@gmail.com>
Date: Mon, 25 Jun 2018 23:20:09 +0200
Subject: [PATCH] lavf/amr: Fix heuristic to avoid detection of repeated
bytes.
---
libavformat/amr.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/libavformat/amr.c b/libavformat/amr.c
index 6cc06bc..de34705 100644
--- a/libavformat/amr.c
+++ b/libavformat/amr.c
@@ -184,12 +184,11 @@ static int amrnb_probe(AVProbeData *p)
while (i < p->buf_size) {
mode = b[i] >> 3 & 0x0F;
if (mode < 9 && (b[i] & 0x4) == 0x4) {
- int last = mode;
+ int last = b[i];
int size = amrnb_packed_size[mode];
while (size--) {
if (b[++i] != last)
break;
- last = b[i];
}
if (size > 0) {
valid++;
@@ -241,12 +240,11 @@ static int amrwb_probe(AVProbeData *p)
while (i < p->buf_size) {
mode = b[i] >> 3 & 0x0F;
if (mode < 10 && (b[i] & 0x4) == 0x4) {
- int last = mode;
+ int last = b[i];
int size = amrwb_packed_size[mode];
while (size--) {
if (b[++i] != last)
break;
- last = b[i];
}
if (size > 0) {
valid++;
--
1.7.10.4
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