On 08.11.2016 21:09, Michael Niedermayer wrote:
> On Tue, Nov 08, 2016 at 07:47:02PM +0100, Andreas Cadhalpun wrote:
>> On 08.11.2016 00:54, Michael Niedermayer wrote:
>>> On Mon, Nov 07, 2016 at 11:49:52PM +0100, Andreas Cadhalpun wrote:
>>>> Signed-off-by: Andreas Cadhalpun <andreas.cadhal...@googlemail.com>
>>>> ---
>>>> libavformat/mpegts.c | 4 ++++
>>>> 1 file changed, 4 insertions(+)
>>>>
>>>> diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
>>>> index fad10c6..77d63f2 100644
>>>> --- a/libavformat/mpegts.c
>>>> +++ b/libavformat/mpegts.c
>>>> @@ -2692,6 +2692,10 @@ static int mpegts_read_header(AVFormatContext *s)
>>>> /* NOTE1: the bitrate is computed without the FEC */
>>>> /* NOTE2: it is only the bitrate of the start of the stream */
>>>> ts->pcr_incr = (pcrs[1] - pcrs[0]) / (packet_count[1] -
>>>> packet_count[0]);
>>>> + if (ts->pcr_incr <= 0) {
>>>> + av_log(s, AV_LOG_ERROR, "invalid pcr increment %d\n",
>>>> ts->pcr_incr);
>>>> + return AVERROR_INVALIDDATA;
>>>> + }
>>>
>>> if a pcr pair is bad i would suggest to run the loop by another
>>> iteration
>>
>> That's a good idea. New patch attached.
>
> LGTM, maybe add a av_log() so the user knows of the issue
Makes sense, patch with added log message is attached.
> (especially
> if all pcr are systematically bad, n which case this would need to be
> adjusted to not fail)
What do you think should be done in that case?
Best regards,
Andreas
>From 02fc2ecef2adb20c3be63a6787c6921f8471ca04 Mon Sep 17 00:00:00 2001
From: Andreas Cadhalpun <andreas.cadhal...@googlemail.com>
Date: Mon, 7 Nov 2016 23:37:59 +0100
Subject: [PATCH] mpegts: prevent division by zero
Signed-off-by: Andreas Cadhalpun <andreas.cadhal...@googlemail.com>
---
libavformat/mpegts.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
index fad10c6..0aa0ad7 100644
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@ -2681,8 +2681,17 @@ static int mpegts_read_header(AVFormatContext *s)
packet_count[nb_pcrs] = nb_packets;
pcrs[nb_pcrs] = pcr_h * 300 + pcr_l;
nb_pcrs++;
- if (nb_pcrs >= 2)
- break;
+ if (nb_pcrs >= 2) {
+ if (pcrs[1] - pcrs[0] > 0) {
+ /* the difference needs to be positive to make sense for bitrate computation */
+ break;
+ } else {
+ av_log(ts->stream, AV_LOG_WARNING, "invalid pcr pair %"PRId64" >= %"PRId64"\n", pcrs[0], pcrs[1]);
+ pcrs[0] = pcrs[1];
+ packet_count[0] = packet_count[1];
+ nb_pcrs--;
+ }
+ }
} else {
finished_reading_packet(s, ts->raw_packet_size);
}
--
2.10.2
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