> > Note that dithering should be done when doing 32bit to 24bit case > and source audio have >24bits used.
Yes - definitely. > >> >> Dithering is only necessary, when converting the data somewhere in between >> (e.g. changing the sample rate while it's in 32bit format), as the code in >> pcm.c (macro ENCODE) simply shifts the 32bit representation by 8bit, >> essentially just dropping the last 8bits. > > Because last 8bits are always zero for that particular case. Exactly. Thanks, Paul, for adding the extra clarifications for the more general case. I saw that you added some more documentation for output_sample_bits (http://patches.libav.org/patch/38964/). Unfortunately, I'm still not entirely sure how to use the parameter - a simple example would be great. Let's say I want to convert 32bit audio to 24bit. The input AVSampleFormat is AV_SAMPLE_FMT_S32, the output sample format as well. But, when writing the result to a file, I want to use AV_CODEC_ID_PCM_S24LE, i.e. the least significant byte is cut off. Therefore, for SWR, I'm calling: av_opt_set_int(swr_context, "dither_method", SWR_DITHER_TRIANGULAR, 0); av_opt_set_int(swr_context, "output_sample_bits", ???, 0); What should I set ??? to? 24, since I'm only using 24bit? Thanks, -hendrik _______________________________________________ Libav-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/libav-user
