aac encoding with ffmpeg result in super short file

Question

So I'm having problem with AAC encoding. I'm trying to encode some synthetic sound waves, but it does not work as expected. The file I get gives just a super short sound when played in VLC. When I play is in ffplay is plays like I expect, but it says "duration: 00:00:00.05" which I suppose says 5 ms. But I encode a lot more than that, and it played more. So VLC plays a super short sound, ffplay plays a longer file (the expected length), but displays it with super short duration, what's going on?

Source: http://pastebin.com/M5MKkEL3

One of the things that looks wrong to me is this: If you look for the variable "audio_time", if you breakpoint it and read it every encode frame, you will get this:

..
Encode frame 8: 0.00010416666666666666
Encode frame 9: 0.00012500000000000000
(and so on)

The diff is: ~0.00002085, which is a 1/1000 of a the diff I expected from ~47 samples frames per second, which is what the encoder wants with 48k sample rate (48k / 1024 = ~47).

So why do I get a thousand of the expected data encoded?

Feel free to point anything suspicious out!

Thanks in advance!

Answer 1

So I found it, in line 75, this was missing:

    time_base.num = per_frame_audio_samples;
    time_base.den = aud_codec_context->sample_rate;
    aud_codec_context->time_base = time_base;

per_frame_audio_samples = 1024 in my case.