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H264 : Strange LOW CPU usage

Posted: 03 Apr 2006 22:51
by Athlon2x
Hello,
i have tried h264 encoding with a new computer :

P4 3ghz / 512mo Ram / XP SP2 no other program installed than VLC.

The source for the transcoding is a DIVX5 movie. I transcode it in h264 512kb/s and MP3 96kb/s for the audio data before to send it on a network over http.

All parameters FFMPEG are the "Default settings".

VLC version : 0.8.5 test2

When start the diffusion, the CPU charge grows to 60%. The quality and the bitrate into the client application respect the parameters.
Perhaps, the video is quite slow.

During the diffusion i have these error message in the server :

Code: Select all

stream_out_transcode debug: late picture skipped (5000) main warning: late buffer for mux input (71000) main warning: late buffer for mux input (97000) stream_out_transcode debug: late picture skipped (97000) main warning: late buffer for mux input (72000) main warning: late buffer for mux input (47000) stream_out_transcode debug: late picture skipped (72000) main warning: late buffer for mux input (37000) stream_out_transcode debug: late picture skipped (32000) main warning: late buffer for mux input (28000) main warning: late buffer for mux input (3000) stream_out_transcode debug: late picture skipped (8000) main warning: late buffer for mux input (27000) main warning: late buffer for mux input (37000) stream_out_transcode debug: late picture skipped (37000) main warning: late buffer for mux input (12000) main warning: late buffer for mux input (3000) stream_out_transcode debug: late picture skipped (13000) main warning: late buffer for mux input (1000) main warning: late buffer for mux input (31000) main warning: late buffer for mux input (6000) stream_out_transcode debug: late picture skipped (11000) main warning: late buffer for mux input (9000) stream_out_transcode debug: late picture skipped (9000) main warning: late buffer for mux input (12000) stream_out_transcode debug: late picture skipped (7000) stream_out_transcode debug: late picture skipped (6000) main warning: late buffer for mux input (27000) main warning: late buffer for mux input (12000) stream_out_transcode debug: late picture skipped (17000) stream_out_transcode debug: late picture skipped (16000) main warning: late buffer for mux input (3000) main warning: late buffer for mux input (31000) main warning: late buffer for mux input (16000) stream_out_transcode debug: late picture skipped (21000) main warning: late buffer for mux input (9000) main warning: late buffer for mux input (19000) stream_out_transcode debug: late picture skipped (19000) main warning: late buffer for mux input (4000) main warning: late buffer for mux input (7000) main warning: late buffer for mux input (22000) stream_out_transcode debug: late picture skipped (17000) stream_out_transcode debug: late picture skipped (15000) main warning: late buffer for mux input (7000) main warning: late buffer for mux input (9000) stream_out_transcode debug: late picture skipped (4000) mux_asf debug: Asf muxer creating header mux_asf debug: pixel aspect-ratio: 1/1 main warning: late buffer for mux input (12000) stream_out_transcode debug: late picture skipped (2000) stream_out_transcode debug: late picture skipped (7000) stream_out_transcode debug: late picture skipped (12000) main warning: late buffer for mux input (37000) main warning: late buffer for mux input (12000) stream_out_transcode debug: late picture skipped (17000) main warning: late buffer for mux input (6000) main warning: late buffer for mux input (16000) stream_out_transcode debug: late picture skipped (16000) main warning: late buffer for mux input (4000) main warning: late buffer for mux input (19000) stream_out_transcode debug: late picture skipped (29000) main warning: late buffer for mux input (17000) main warning: late buffer for mux input (37000) stream_out_transcode debug: late picture skipped (43000) main warning: late buffer for mux input (3000) stream_out_transcode debug: late picture skipped (3000) main warning: late buffer for mux input (6000) stream_out_transcode debug: late picture skipped (1000) main warning: late buffer for mux input (9000) stream_out_transcode debug: late picture skipped (15000) main warning: late buffer for mux input (3000) main warning: late buffer for mux input (23000) main warning: late buffer for mux input (3000) stream_out_transcode debug: late picture skipped (29000) main warning: late buffer for mux input (1000) main warning: late buffer for mux input (47000) main warning: late buffer for mux input (22000) stream_out_transcode debug: late picture skipped (27000) stream_out_transcode debug: late picture skipped (2000) main warning: late buffer for mux input (22000) main warning: late buffer for mux input (42000) main warning: late buffer for mux input (2000) stream_out_transcode debug: late picture skipped (47000) main warning: late buffer for mux input (12000) stream_out_transcode debug: late picture skipped (7000) main warning: late buffer for mux input (16000) stream_out_transcode debug: late picture skipped (6000)
It might be the reason why the video is slow.

As the CPU is not overcharged by the transcoding, what could create these errors and slowdown the video ?

Thanks a lot for your explanations !

Posted: 08 Apr 2006 21:02
by Athlon2x
no one ?

Posted: 18 Apr 2006 16:15
by Guest
Same problem here. divx/mp3->theora/vorbis transcoding.

Me too

Posted: 19 Apr 2006 02:58
by bbishopski
i have similar problem - my source is RTSP and then transcoding to h264 and streaming out over UDP.

Actually, I'm surprised it works as well as it does - very complicated to do - no other program I can find does this.

However, I have to tweak the cache parameters in order to get it to work - and then I have a 2-3 second delay.

Since you're streaming over HTTP, I'm not sure any of the cache settings will help - there is one http cache setting, but I thought it would be for input not output. There's also an RTSP and UDP cache setting.

I haven't looked at the source yet, but you might have a look for that error message.

What happens for me is the lower I set my cache the more of those error messages I see. When I increase cache, I see fewer or none of those errors.

Not sure how my problem relates to yours since yours is reading from disk. Is there a disk cache setting?