[FFmpeg-user] Full description of ffmpeg input - avoid analysis and probing of input files

[Thomas Seilund]

Hi All,

I have a process where I have a number of different inputs to ffmpeg.

Typically I create inputs using ffmpeg, ie.

ffmpeg -loop 1 -re -i 1.png -c libx264 -preset ultrafast -s 200x100 -r 24 - 
pix_fmt yuv420p -f mpegts udp://a.b:1235
ffmpeg -loop 1 -re -i 2.png -c libx264 -preset ultrafast -s 400x200 -r 24 - 
pix_fmt yuv420p -f mpegts udp://a.b:1236
ffmpeg -loop 1 -re -i 3.png -c libx264 -preset ultrafast -s 200x100 -r 24 - 
pix_fmt yuv420p -f mpegts udp://a.b:1237

When I read these input streams I often see that ffmpeg is not able to  
determine the input. See ex. below.

How can I make ffmpeg pick up the input without any analysis or probing?

Will a set of input parameters make it possible for ffmpeg to pick up the  
input right away?

Can I do an ffprobe on the input a determine the needed input parameters  
for ffmpeg?


Ex:

ffplay -i udp://a.b:1235

.
.
.

[h264 @ 0x7f552002b400] decode_slice_header error
[h264 @ 0x7f552002b400] no frame!
[h264 @ 0x7f552002b400] non-existing PPS 0 referenced    0B f=0/0
     Last message repeated 1 times
[h264 @ 0x7f552002b400] decode_slice_header error
[h264 @ 0x7f552002b400] no frame!
[h264 @ 0x7f552002b400] non-existing PPS 0 referenced    0B f=0/0
     Last message repeated 1 times
[h264 @ 0x7f552002b400] decode_slice_header error
[h264 @ 0x7f552002b400] no frame!
[h264 @ 0x7f552002b400] non-existing PPS 0 referenced    0B f=0/0
[mpegts @ 0x7f55200008c0] decoding for stream 0 failed
[mpegts @ 0x7f55200008c0] Could not find codec parameters for stream 0  
(Video: h264 ([27][0][0][0] / 0x001B), none): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize'  
options
udp://a.b:1235: could not find codec parameters


Any help would be appriciated !


Thanks Thomas S