[Ffmpeg-devel] [PATCH] THP PCM decoder (GSoC Qualification)
Wed Apr 4 12:33:21 CEST 2007
Michael Niedermayer <michaelni at gmx.at> writes:
>> >> When I decode the other channel it seems to work as well. So I assume
>> >> the problem is in how I fill the output buffer and how I tell ffmpeg
>> >> the format (stereo, interleaved samples) of this data. How does one
>> >> in general deal with stereo from a decoder?
>> > stereo in ffmpeg is always
>> > channel0-sample0, channel1-sample0, channel0-sample1, channel1-sample1, channel0-sample2, channel1-sample2, ...
>> Well, I have this now and it works... kinda. When I am playing either
>> one of the two channels as mono sound, it works. When I am using both
>> channels, there is some kind of noise/cracks. The noise is not there
>> all the time and it is not very loud, but I am mentioning this because
>> there must still be something that I do wrong...
> hmm, is AVCodecContext.channels set correctly
> does it also sound bad if you dump it to a file or let ffmpeg transcode it
> to pcm wav and then play that ... ?
Same problem... I put it online, in case you want to hear it:
>> + init_get_bits(&gb, src, buf_size * 8);
>> + src += buf_size;
>> + get_bits(&gb, 32); /* Channel size */
>> + samplecnt = get_bits(&gb, 32);
> get_bits does have undefined behavior when reading more then 17-25 bits
> depending on the used bitreader, get_bits_long() is a better choice
Sorry, I forgot to change this.
>> + uint8_t index = get_bits (&gb, 4) & 7;
> iam curious what the removed bit does, is it always 0 ?
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