On Apr 24, 2013, at 4:54 PM, Paul B Mahol <[email protected]> wrote: > You call av_samples_alloc_array_and_samples() with align set to 0, which means > channel data planes are aligned along 32 byte boundary. Is this really the > case? > > Set align argument to 1 if to make them aligned along 1 byte boundary.
Here is the information on the sample buffer received from QTKit which is being used to fill the source data array: 2013-04-24 17:06:58.653 QTFFmpeg[2732:d407] Linear PCM, 32 bit little-endian floating point, 2 channels, 44100 Hz 2013-04-24 17:06:58.654 QTFFmpeg[2732:d407] Bytes per frame: 4 2013-04-24 17:06:58.654 QTFFmpeg[2732:d407] Frames per packet: 1 2013-04-24 17:06:58.655 QTFFmpeg[2732:d407] Bits per channel: 32 2013-04-24 17:06:58.655 QTFFmpeg[2732:d407] Is packed? YES 2013-04-24 17:06:58.655 QTFFmpeg[2732:d407] Is high aligned? NO 2013-04-24 17:06:58.656 QTFFmpeg[2732:d407] Channels per frame: 2 So to answer your question, provided that I've understood it correctly, samples are packed, therefore should be aligned on the full 32-bit boundary, and thus align should be set to 0. But for the sake of curiosity, I changed align to 1 (for all functions with align) and it made no difference in the audio distortion...same as before. I then tried setting the align parameter to 1 on only the filling of the source data array -- distorted audio still, but seemed to cut the whole track short. To the best of my knowledge, a packed sample buffer should not need high alignment (which I presume is what you mean by the 1 byte boundary). If I've misunderstood your question, let me know. Thanks, Brad _______________________________________________ Libav-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/libav-user
