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some audio problems fixed, missing files added

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git-svn-id: file:///home/notaz/opt/svn/PicoDrive@31 be3aeb3a-fb24-0410-a615-afba39da0efa
This commit is contained in:
notaz 2007-02-08 20:12:45 +00:00
parent 7a93adeb29
commit abe0ea43b5
9 changed files with 583 additions and 288 deletions
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134
platform/gp2x/mp3.c Normal file
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@ -0,0 +1,134 @@
#include <stdio.h>
#include <string.h>
#include "../../Pico/sound/mix.h"
#include "code940/940shared.h"
#include "helix/pub/mp3dec.h"
static short mp3_out_buffer[2*1152];
static HMP3Decoder mp3dec = 0;
static int mp3_buffer_offs = 0;
extern _940_ctl_t *shared_ctl;
extern unsigned char *mp3_mem;
extern int PsndRate;
static int try_get_header(unsigned char *buff, MP3FrameInfo *fi)
{
int ret, offs1, offs = 0;
while (1)
{
offs1 = MP3FindSyncWord(buff + offs, 2048 - offs);
if (offs1 < 0) return -2;
offs += offs1;
if (2048 - offs < 4) return -3;
// printf("trying header %08x\n", *(int *)(buff + offs));
ret = MP3GetNextFrameInfo(mp3dec, fi, buff + offs);
if (ret == 0 && fi->bitrate != 0) break;
offs++;
}
return ret;
}
int mp3_get_bitrate(FILE *f, int len)
{
unsigned char buff[2048];
MP3FrameInfo fi;
int ret;
memset(buff, 0, 2048);
if (!mp3dec) mp3dec = MP3InitDecoder();
fseek(f, 0, SEEK_SET);
ret = fread(buff, 1, 2048, f);
fseek(f, 0, SEEK_SET);
if (ret <= 0) return -1;
ret = try_get_header(buff, &fi);
if (ret != 0 || fi.bitrate == 0) {
// try to read somewhere around the middle
fseek(f, len>>1, SEEK_SET);
fread(buff, 1, 2048, f);
fseek(f, 0, SEEK_SET);
ret = try_get_header(buff, &fi);
}
if (ret != 0) return ret;
// printf("bitrate: %i\n", fi.bitrate / 1000);
return fi.bitrate / 1000;
}
static void mp3_decode(void)
{
// tried copying this to cached mem, no improvement noticed
int mp3_offs = shared_ctl->mp3_offs;
unsigned char *readPtr = mp3_mem + mp3_offs;
int bytesLeft = shared_ctl->mp3_len - mp3_offs;
int offset; // frame offset from readPtr
int err;
if (bytesLeft <= 0) return; // EOF, nothing to do
offset = MP3FindSyncWord(readPtr, bytesLeft);
if (offset < 0) {
shared_ctl->mp3_offs = shared_ctl->mp3_len;
return; // EOF
}
readPtr += offset;
bytesLeft -= offset;
err = MP3Decode(mp3dec, &readPtr, &bytesLeft, mp3_out_buffer, 0);
if (err) {
if (err == ERR_MP3_INDATA_UNDERFLOW) {
shared_ctl->mp3_offs = shared_ctl->mp3_len; // EOF
return;
} else if (err <= -6 && err >= -12) {
// ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*
// just try to skip the offending frame..
readPtr++;
}
shared_ctl->mp3_errors++;
shared_ctl->mp3_lasterr = err;
}
shared_ctl->mp3_offs = readPtr - mp3_mem;
}
void mp3_update_local(int *buffer, int length, int stereo)
{
int length_mp3, shr = 0;
void (*mix_samples)(int *dest_buf, short *mp3_buf, int count) = mix_16h_to_32;
length_mp3 = length;
if (PsndRate == 22050) { mix_samples = mix_16h_to_32_s1; length_mp3 <<= 1; shr = 1; }
else if (PsndRate == 11025) { mix_samples = mix_16h_to_32_s2; length_mp3 <<= 2; shr = 2; }
if (1152 - mp3_buffer_offs >= length_mp3) {
mix_samples(buffer, mp3_out_buffer + mp3_buffer_offs*2, length<<1);
mp3_buffer_offs += length_mp3;
} else {
int left = 1152 - mp3_buffer_offs;
mix_samples(buffer, mp3_out_buffer + mp3_buffer_offs*2, (left>>shr)<<1);
mp3_decode();
mp3_buffer_offs = length_mp3 - left;
mix_samples(buffer + ((left>>shr)<<1), mp3_out_buffer, (mp3_buffer_offs>>shr)<<1);
}
}
void mp3_start_local(void)
{
mp3_buffer_offs = 0;
mp3_decode();
}