[FFmpeg-devel] [PATCH] lavfi: asetnsamples: fix enlarging fifo

[Andrey Utkin]

2012/8/7 Stefano Sabatini <stefasab at gmail.com>:
> This is overallocating the fifo.
>
> We need to add nb_samples to the fifo, but only FIFO_SPACE <
> nb_samples are available, so we increase the fifo max size to
> FIFO_SIZE + nb_samples.
>
> We have:
> FIFO_SIZE + FIFO_SPACE = AVAILABLE_SIZE
>
> FIFO_SPACE = nb_samples
>
> so it must result:
> FIFO_SIZE + nb_samples = AVAILABLE_SIZE
>
> What am I missing?

You're missing the fact that av_audio_fifo_size() returns not the full
memory capacity of the object, but the amount of data loaded into it.
The same principle applies to AVFifoBuffer. This is confusing moment
indeed.

/**
 * Get the current number of samples in the AVAudioFifo available for reading.
 *
 * @param af  the AVAudioFifo to query
 * @return    number of samples available for reading
 */
int av_audio_fifo_size(AVAudioFifo *af);

-- 
Andrey Utkin