[mad-dev] mad on arm processor -- strange problems.
Sun, 26 May 2002 20:16:33 -0700
Rob Leslie wrote:
> In order for minimad to use mmap(), it's necessary to invoke it like this:
> minimad <input.mp3 >output.pcm
That's how I did invoke it, before the change. It still failed.
Perhaps because the location of the mp3 file is nfs mounted, though
that's just a guess.
> I don't think the problem is with the high-level API since both minimad
> and madplay use it.
> Perhaps the problem is the byte order of the output samples. minimad
> always outputs little-endian samples, but madplay's raw output uses the
> native endian format of your host. Is your audio driver expecting
> big-endian samples?
To test this, I went ahead and forced madplay to little-endian :
# if defined(WORDS_BIGENDIAN)
# define audio_pcm_s32 audio_pcm_s32be
# define audio_pcm_s24 audio_pcm_s24be
# define audio_pcm_s16 audio_pcm_s16be
# define audio_pcm_s32 audio_pcm_s32le
# define audio_pcm_s24 audio_pcm_s24le
# define audio_pcm_s16 audio_pcm_s16le
It played the audio just fine. Perhaps it has something to do with
minimad's scale() function (I'm currently using it as-is, in my code)?
I might try ripping out some of the audio massaging code from
audio_raw.c and putting into my code to see what it does. Otherwise, do
you have any other thoughts?
One other question -- with the high-level API's call of
mad_stream_buffer(), does it want data in a prefered size? Or does it
have to end on some multiple of some size?