On 02.11.2016 13:07, Michael Niedermayer wrote:
> On Sat, Oct 22, 2016 at 01:16:00AM +0200, Andreas Cadhalpun wrote:
>> utils.c | 12 ++++++++++++
>> 1 file changed, 12 insertions(+)
>> ffefc22756b774cb7652587207ae66cfbf681be3
>> 0001-avformat-close-parser-if-codec-changed.patch
>> From 9de87a4fb2c6c6311a11a2da5de8554a71adfa66 Mon Sep 17 00:00:00 2001
>> From: Andreas Cadhalpun <andreas.cadhal...@googlemail.com>
>> Date: Mon, 17 Oct 2016 20:26:51 +0200
>> Subject: [PATCH] avformat: close parser if codec changed
>>
>> The parser depends on the codec and thus must not be used with a different
>> one.
>> If it is, the 'avctx->codec_id == s->parser->codec_ids[0] ...' assert in
>> av_parser_parse2 gets triggered.
>>
>> Signed-off-by: Andreas Cadhalpun <andreas.cadhal...@googlemail.com>
>> ---
>> libavformat/utils.c | 12 ++++++++++++
>> 1 file changed, 12 insertions(+)
>>
>> diff --git a/libavformat/utils.c b/libavformat/utils.c
>> index 70dbfa1..a8a78ed 100644
>> --- a/libavformat/utils.c
>> +++ b/libavformat/utils.c
>> @@ -480,6 +480,12 @@ static int update_stream_avctx(AVFormatContext *s)
>> if (!st->internal->need_context_update)
>> continue;
>>
>> + /* close parser, because it depends on the codec */
>> + if (st->parser && st->internal->avctx->codec_id !=
>> st->codecpar->codec_id) {
>> + av_parser_close(st->parser);
>> + st->parser = NULL;
>> + }
>> +
>> /* update internal codec context, for the parser */
>> ret = avcodec_parameters_to_context(st->internal->avctx,
>> st->codecpar);
>> if (ret < 0)
>> @@ -1515,6 +1521,12 @@ static int read_frame_internal(AVFormatContext *s,
>> AVPacket *pkt)
>> st->info->found_decoder = 0;
>> }
>>
>> + /* close parser, because it depends on the codec */
>> + if (st->parser && st->internal->avctx->codec_id !=
>> st->codecpar->codec_id) {
>> + av_parser_close(st->parser);
>> + st->parser = NULL;
>> + }
>> +
>
> what if the codec id differs but both are supported by the parser ?
> AVCodecParser has a list of 5 codec ids ?
>
> I didnt find a testcase where this makes a difference, just wondering
I think the parser should be re-initialized in that case, too.
For example the ac3 parser stores the codec_id in the parser context with:
if(hdr.bitstream_id>10)
hdr_info->codec_id = AV_CODEC_ID_EAC3;
else if (hdr_info->codec_id == AV_CODEC_ID_NONE)
hdr_info->codec_id = AV_CODEC_ID_AC3;
So if it is first AV_CODEC_ID_EAC3 and then AV_CODEC_ID_AC3, this wouldn't
be updated and the parser would change the avctx codec_id back, which
seems wrong.
> the patch seems fine otherwise
OK, pushed.
Best regards,
Andreas
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