On 6 November 2014 22:55, Michael Niedermayer <michae...@gmx.at> wrote:
> On Thu, Nov 06, 2014 at 09:27:45PM +0100, Lukasz Marek wrote:
> > On 06.11.2014 01:32, Michael Niedermayer wrote:
> > >On Thu, Nov 06, 2014 at 12:59:45AM +0100, Lukasz Marek wrote:
> > >>new_output_stream creates a codec context with arbitraty picked codec.
> > >>Later data is updated, but priv_data are left alone.
> > >>There is a bit chance there is a mismatch between codecs.
> > >>
> > >>Signed-off-by: Lukasz Marek <lukasz.m.lu...@gmail.com>
> > >>---
> > >> ffmpeg_opt.c | 16 ++++++++++++++++
> > >> libavformat/ffmdec.c | 6 ++++--
> > >> 2 files changed, 20 insertions(+), 2 deletions(-)
> > >
> > >with this fate-lavf-ffm crashes
> > >
> > >==10836== Invalid write of size 8
> > >==10836== at 0x935442: decode_init (mpegaudiodec_template.c:419)
> > >==10836== by 0xA69226: avcodec_open2 (utils.c:1614)
> > >==10836== by 0x64CC5F: avformat_find_stream_info (utils.c:3053)
> > >==10836== by 0x41C2D7: open_input_file (ffmpeg_opt.c:886)
> > >==10836== by 0x42427A: open_files (ffmpeg_opt.c:2699)
> > >==10836== by 0x4243F8: ffmpeg_parse_options (ffmpeg_opt.c:2736)
> > >==10836== by 0x43762E: main (ffmpeg.c:3861)
> > >==10836== Address 0x10f072b0 is not stack'd, malloc'd or (recently)
> free'd
> > >==10836==
> > >==10836== Invalid write of size 8
> > >==10836== at 0xDC67D0: avpriv_float_dsp_init (float_dsp.c:120)
> > >==10836== by 0x93546B: decode_init (mpegaudiodec_template.c:421)
> > >==10836== by 0xA69226: avcodec_open2 (utils.c:1614)
> > >==10836== by 0x64CC5F: avformat_find_stream_info (utils.c:3053)
> > >==10836== by 0x41C2D7: open_input_file (ffmpeg_opt.c:886)
> > >==10836== by 0x42427A: open_files (ffmpeg_opt.c:2699)
> > >==10836== by 0x4243F8: ffmpeg_parse_options (ffmpeg_opt.c:2736)
> > >==10836== by 0x43762E: main (ffmpeg.c:3861)
> > >==10836== Address 0x10f072e8 is not stack'd, malloc'd or (recently)
> free'd
> > >and pages more
> >
> > I tried to debug it, but there is too much code to read to handle
> > one very specific case and I'm not sure there is other, better
> > solution.
>
> > Probably, I haven't check, clear solution would be to clear
> > priv_data in read_ffserver_streams right after copy_context, and set
> > it to NULL, but I will need private data soon to support it in
> > ffserver.
>
> Maybe iam missing something but why does the ffm demuxer attempt to
> setup a encoder instead of exporting the "recommanded" encoder
> settings as name-value pairs (possibly in metadata) and ffmpeg then
> sets up the encoder streams based on that instead of copying
> contexts
>
Probably you are not mistaken.
After sending I had second thoughts, probably it would be better to do one
of the followings:
- add option to muxer instead to control context should be read/write from
file (now is always written)
- export parsing function that is major part of read_header so ffmpeg can
pass its own context and params will be read. This has disadvantage that
ffmpeg would need ffm's private header. Already present in ffserver though.
- your solution
> Trying to set the encoder contexts up in a demuxer (which normally
> would interface to decoders not encoders) seems odd to me
> Though of course this is how it was designed before the patch already
>
Yes, but maybe its time to clean hack and not to add new one. In new patch
I just clear possibly incorrect priv_data.
I will come back to during the weekend when I want to finish private
options handling in ffserver
From 9d3188dd3fadfad47ef4cbe2073604d4cd7ebdc2 Mon Sep 17 00:00:00 2001
From: Lukasz Marek <lukasz.m.lu...@gmail.com>
Date: Fri, 7 Nov 2014 09:05:41 +0100
Subject: [PATCH] ffmpeg_opt: free incorrect priv_data for feed stream
new_output_stream creates a codec context with arbitraty picked codec.
Later data is updated, but priv_data are left alone.
There is a bit chance there is a mismatch between codecs.
Signed-off-by: Lukasz Marek <lukasz.m.lu...@gmail.com>
---
ffmpeg_opt.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/ffmpeg_opt.c b/ffmpeg_opt.c
index 1757dcc..454da98 100644
--- a/ffmpeg_opt.c
+++ b/ffmpeg_opt.c
@@ -1649,6 +1649,10 @@ static int read_ffserver_streams(OptionsContext *o, AVFormatContext *s, const ch
else if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && !ost->stream_copy)
choose_pixel_fmt(st, st->codec, codec, st->codec->pix_fmt);
avcodec_copy_context(ost->enc_ctx, st->codec);
+ if (ost->enc_ctx->priv_data) {
+ av_opt_free(ost->enc_ctx->priv_data);
+ av_freep(&ost->enc_ctx->priv_data);
+ }
}
avformat_close_input(&ic);
--
1.9.1
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