Hi.

> Note that here you are sending PPS and SPS "in band" (try adding "-vglobal 1"
>  if you want "out of band" SPS and PPS. You should see a new
>  "sprop-parameter-sets=..." entry in the SDP.

I tried to use the out-band SDP generated with the -vglobal 1 flag
together with my app, and now VLC managed to display a video window,
but it's filled with gray noise and many errors (which never appeared
for the command line):

ffmpeg debug: concealing 681 DC, 681 AC, 681 MV errors
 ([EMAIL PROTECTED])
ffmpeg warning: cbp too large (61) at 22 2
 ([EMAIL PROTECTED])
ffmpeg warning: error while decoding MB 22 2
 ([EMAIL PROTECTED])
ffmpeg debug: concealing 657 DC, 657 AC, 657 MV errors
 ([EMAIL PROTECTED])
ffmpeg warning: top block unavailable for requested intra mode at 29 0
 ([EMAIL PROTECTED])
ffmpeg warning: error while decoding MB 29 0
 ([EMAIL PROTECTED])
ffmpeg debug: concealing 690 DC, 690 AC, 690 MV errors
 ([EMAIL PROTECTED])
ffmpeg warning: top block unavailable for requested intra mode at 29 0
 ([EMAIL PROTECTED])
ffmpeg warning: error while decoding MB 29 0
 ([EMAIL PROTECTED])
ffmpeg debug: concealing 690 DC, 690 AC, 690 MV errors
 ([EMAIL PROTECTED])
ffmpeg warning: mb_type 57 in P slice too large at 7 4
 ([EMAIL PROTECTED])
ffmpeg warning: error while decoding MB 7 4
 ([EMAIL PROTECTED])
ffmpeg debug: concealing 612 DC, 612 AC, 612 MV errors
 ([EMAIL PROTECTED])
ffmpeg warning: out of range intra chroma pred mode at 23 5
 ([EMAIL PROTECTED])
ffmpeg warning: error while decoding MB 23 5

It might be something in my code, but when I redirect the output to
disk - it saves a perfectly valid MP4 file.


> This generally happens when you send a stream that does not contain any PPS 
> and
>  SPS (so, you are supposed to send them "out of band" in an SDP entry), but 
> the
>  SDP does not contain a proper "sprop-parameter-sets=..." entry.

>  Any chance you are setting the CODEC_FLAG_GLOBAL_HEADER in the 
> AVCodecContext,
>  but you are using the same SDP used in the previous case (whe PPS and SPS 
> were
>  in band)? (In this case, you just need to re-generate the SDP by calling
>  avf_sdp_create() in your code).

You are right - I used this flag (as it was mentioned in the OutputExample).

What are the benefits of using out-band, compared to in-band - does it
means less bandwidth required?

>
>  Or maybe the extradata are malformed (it happens when reading the H.264 video
>  from an mp4 or mov file. Maybe this can be fixed by using a proper bitstream
>  filter).
>
>  Can you have a look at the SDP, and check the sprop-parameter-sets attribute?
>  Also, how are you encoding the h264 video?

I'm encoding the h.264 with standard av_encode_frame() function.

As I explained, I took a working example which writes to disk, and
basically redirected it to RTP. Now, only this gray noise + error
messages remain - any idea what is wrong?

Thanks in advance.
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