external/rktoolkit/minimad.c

2  * libmad - MPEG audio decoder library
3  * Copyright (C) 2000-2004 Underbit Technologies, Inc.
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
30  * This is perhaps the simplest example use of the MAD high-level API.
31  * Standard input is mapped into memory via mmap(), then the high-level API
33  * callback converts MAD's high-resolution PCM samples to 16 bits, then
34  * writes them to standard output in little-endian, stereo-interleaved
48   if (fstat(STDIN_FILENO, &stat) == -1 ||  in main()
58   if (munmap(fdm, stat.st_size) == -1)  in main()
89   if (!buffer->length)  in input()
92   mad_stream_buffer(stream, buffer->start, buffer->length);  in input()
94   buffer->length = 0;  in input()
101  * scaling of MAD's high-resolution samples down to 16 bits. It does not
103  * obtain any exceptional audio quality. It is therefore not recommended to
104  * use this routine if high-quality output is desired.
111   sample += (1L << (MAD_F_FRACBITS - 16));  in scale()
115     sample = MAD_F_ONE - 1;  in scale()
116   else if (sample < -MAD_F_ONE)  in scale()
117     sample = -MAD_F_ONE;  in scale()
120   return sample >> (MAD_F_FRACBITS + 1 - 16);  in scale()
137   /* pcm->samplerate contains the sampling frequency */  in output()
139   nchannels = pcm->channels;  in output()
140   nsamples  = pcm->length;  in output()
141   left_ch   = pcm->samples[0];  in output()
142   right_ch  = pcm->samples[1];  in output()
144   while (nsamples--) {  in output()
147     /* output sample(s) in 16-bit signed little-endian PCM */  in output()
165  * error occurs. The error is indicated by stream->error; the list of
178 	  stream->error, mad_stream_errorstr(stream),  in error()
179 	  stream->this_frame - buffer->start);  in error()