[FFmpeg-devel] [PATCH] forward ASF tags to RTSP for MS-RTSP

[Aurelien Jacobs]

On Wed, Jan 12, 2011 at 10:55:08PM -0500, Ronald S. Bultje wrote:
> Hi,
> 
> On Wed, Jan 12, 2011 at 8:07 AM, Aurelien Jacobs <aurel at gnuage.org> wrote:
> > On Tue, Jan 11, 2011 at 10:39:37PM -0500, Ronald S. Bultje wrote:
> >> On Mon, Jan 3, 2011 at 6:48 PM, Aurelien Jacobs <aurel at gnuage.org> wrote:
> >> > On Mon, Jan 03, 2011 at 03:06:20PM -0500, Justin Ruggles wrote:
> >> >> On 01/03/2011 01:22 PM, Ronald S. Bultje wrote:
> >> >>
> >> >> > Hi,
> >> >> >
> >> >> > On Mon, Jan 3, 2011 at 1:17 PM, Martin Storsj? <martin at martin.st> wrote:
> >> >> >> On Mon, 3 Jan 2011, Ronald S. Bultje wrote:
> >> >> >>
> >> >> >>> for chained demuxers, we need to manually FW tags, this patch does it
> >> >> >>> for MS-RTSP. Fixes issue 2478.
> >> >> >>
> >> >> >> Looks good to me.
> >> >> >>
> >> >> >> As future improvment - should we make this into a reusable function? I
> >> >> >> guess something similar might be needed for other
> >> >> >> full-container-within-another-container setups (like mpegts in RTP).
> >> >> >
> >> >> > Sounds like a good plan - but I'd like to leave that question to other
> >> >> > metadata experts. Anton? Aurel? Baptiste? Michael?
> >> >>
> >> >>
> >> >> search ffmpeg.c for "autocopy" and you'll find lots of code very similar
> >> >> to this. ?So adding it to the public API might be a good idea.
> >> >
> >> > I agree that a public metadata_copy API would be useful.
> >> > Something like:
> >> > ? ?int av_metadata_copy(AVMetadata **dest, AVMetadata *src);
> >>
> >> Has anyone implemented this since then?
> >
> > Not that I know of, but IIRC there was some patches sent here a long
> > time ago proposing something similar (and never accepted).
> >
> >> Or should I do it myself?
> >
> > This shouldn't be hard to do, so I would say yes, go ahead.
> 
> See attached. If wanted I can apply in two steps. I called in ff_*()
> because we may want to do stuff before making it public (but then
> again, ffmpeg.c uses it so maybe it should be public, in that case
> please comment on API also.)

IMHO it is mandatory to make it public to use it in ffmpeg.c.
Overall, patch looks OK to me.

> Index: libavformat/metadata.c
> ===================================================================
> --- libavformat/metadata.c	(revision 26130)
> +++ libavformat/metadata.c	(working copy)
> @@ -158,3 +158,11 @@
>      for (i=0; i<ctx->nb_programs; i++)
>          ff_metadata_conv(&ctx->programs[i]->metadata, d_conv, s_conv);
>  }
> +
> +void ff_metadata_copy(AVMetadata **dst, AVMetadata *src, int dst_flags)
> +{
> +    AVMetadataTag *t = NULL;
> +
> +    while ((t = av_metadata_get(src, "", t, AV_METADATA_IGNORE_SUFFIX)))
> +        av_metadata_set2(dst, t->key, t->value, dst_flags);
> +}

I would personnaly rename 'dst_flags' to 'flags' but that's just
unimportant bikeshed.

> Index: libavformat/rtpdec_asf.c
> ===================================================================
> --- libavformat/rtpdec_asf.c	(revision 26130)
> +++ libavformat/rtpdec_asf.c	(working copy)
> @@ -112,6 +112,7 @@
>          ret = av_open_input_stream(&rt->asf_ctx, &pb, "", &asf_demuxer, NULL);
>          if (ret < 0)
>              return ret;
> +        ff_metadata_copy(&s->metadata, rt->asf_ctx->metadata, 0);
>          rt->asf_pb_pos = url_ftell(&pb);
>          av_free(buf);
>          rt->asf_ctx->pb = NULL;

IMHO this should be committed separately.

Aurel