[FFmpeg-devel] [RFC] ac3enc: how do I force ac3 encodertooutput frames with the same size?

Piotr Bandurski ami_stuff at o2.pl
Tue Dec 25 18:41:03 CET 2012


Hi,

> if you want 280 then you need 16078.125 bits per second
> 
> you could try
> 16078

coded_frame_size: 279

[ac3 @ 018ecb98] hdr.bitstream_id: 10
[ac3 @ 018ecb98] hdr.frame_size: 278
[ac3 @ 018ecb98] hdr.bitstream_id: 10
[ac3 @ 018ecb98] hdr.frame_size: 280
[ac3 @ 018ecb98] hdr.bitstream_id: 10
[ac3 @ 018ecb98] hdr.frame_size: 280
[ac3 @ 018ecb98] hdr.bitstream_id: 10
[ac3 @ 018ecb98] hdr.frame_size: 280

> 16079

coded_frame_size: 280

[ac3 @ 018ecb98] hdr.bitstream_id: 10
[ac3 @ 018ecb98] hdr.frame_size: 278
[ac3 @ 018ecb98] hdr.bitstream_id: 10
[ac3 @ 018ecb98] hdr.frame_size: 280
[ac3 @ 018ecb98] hdr.bitstream_id: 10
[ac3 @ 018ecb98] hdr.frame_size: 280
[ac3 @ 018ecb98] hdr.bitstream_id: 10
[ac3 @ 018ecb98] hdr.frame_size: 280

> 18375

coded_frame_size: 320

[ac3 @ 018ecb98] hdr.bitstream_id: 10
[ac3 @ 018ecb98] hdr.frame_size: 348
[ac3 @ 018ecb98] hdr.bitstream_id: 10
[ac3 @ 018ecb98] hdr.frame_size: 348
[ac3 @ 018ecb98] hdr.bitstream_id: 10
[ac3 @ 018ecb98] hdr.frame_size: 348
[ac3 @ 018ecb98] hdr.bitstream_id: 10
[ac3 @ 018ecb98] hdr.frame_size: 348

> as bitrates
> 
> maybe the results of these tests would give hints at where the problem
> is

Here is a sample from real encoder with hdr.frame_size: 278 for all of the frames:

http://www.datafilehost.com/download-68635511.html

Regards



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