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

[Piotr Bandurski]

Hi,

> i assume none of these plays with the real decoder ?

16789 plays ok (looks like RealPlayer skips 279 frame and decodes correctly 280 frames),
but generally ac3 dnet have 11 defined modes:

00 -  8kHz mono 16kbps ac3 (low response)
01 - 11kHz mono 16kbps ac3 (medium response)
02 - 11kHz mono 16kbps ac3 (high response)
03 -  8kHz ster 20kbps ac3
04 - 22kHz mono 40kbps ac3
05 - 16kHz ster 40kbps ac3
06 - 44kHz mono 80kbps ac3
07 - 32kHz ster 80kbps ac3
08 -  8kHz mono  8kbps ac3
09 -  8kHz mono 12kbps ac3
10 - 16kHz mono 32kbps ac3
11 - 11kHz ster 32kbps ac3

so this code from rmenc.c is wrong as well:

            switch(sample_rate) {
            case 48000:
            case 24000:
            case 12000:
                fscode = 1;
                break;
            default:
            case 44100:
            case 22050:
            case 11025:
                fscode = 2;
                break;
            case 32000:
            case 16000:
            case 8000:
                fscode = 3;
            }
            avio_wb16(s, fscode); /* codec additional info, for AC-3, seems
                                     to be a frequency code */

Regards