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support mp3 decoding over libavcodec

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This commit is contained in:
notaz 2013-07-01 03:40:31 +03:00
parent 90f0dedf83
commit fc11dd059b
9 changed files with 342 additions and 158 deletions
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167
platform/common/mp3_helix.c
View file

@ -16,74 +16,15 @@
#include "mp3.h"
#include "lprintf.h"
static HMP3Decoder mp3dec = 0;
static FILE *mp3_current_file = NULL;
static int mp3_file_len = 0, mp3_file_pos = 0;
static int mp3_buffer_offs = 0;
static unsigned char mp3_input_buffer[2*1024];
static HMP3Decoder mp3dec;
static unsigned char mp3_input_buffer[2 * 1024];
#ifdef __GP2X__
#define mp3_update mp3_update_local
#define mp3_start_play mp3_start_play_local
#endif
static int try_get_header(unsigned char *buff, MP3FrameInfo *fi)
{
int ret, offs1, offs = 0;
while (1)
{
offs1 = mp3_find_sync_word(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(void *f_, int len)
{
unsigned char buff[2048];
MP3FrameInfo fi;
FILE *f = f_;
int ret;
memset(buff, 0, sizeof(buff));
if (mp3dec)
MP3FreeDecoder(mp3dec);
mp3dec = MP3InitDecoder();
fseek(f, 0, SEEK_SET);
ret = fread(buff, 1, sizeof(buff), 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 int mp3_decode(void)
int mp3dec_decode(FILE *f, int *file_pos, int file_len)
{
unsigned char *readPtr;
int bytesLeft;
@ -93,16 +34,17 @@ static int mp3_decode(void)
do
{
if (mp3_file_pos >= mp3_file_len)
if (*file_pos >= file_len)
return 1; /* EOF, nothing to do */
fseek(mp3_current_file, mp3_file_pos, SEEK_SET);
bytesLeft = fread(mp3_input_buffer, 1, sizeof(mp3_input_buffer), mp3_current_file);
fseek(f, *file_pos, SEEK_SET);
bytesLeft = fread(mp3_input_buffer, 1, sizeof(mp3_input_buffer), f);
offset = mp3_find_sync_word(mp3_input_buffer, bytesLeft);
if (offset < 0) {
lprintf("find_sync_word (%i/%i) err %i\n", mp3_file_pos, mp3_file_len, offset);
mp3_file_pos = mp3_file_len;
lprintf("find_sync_word (%i/%i) err %i\n",
*file_pos, file_len, offset);
*file_pos = file_len;
return 1; // EOF
}
readPtr = mp3_input_buffer + offset;
@ -113,112 +55,41 @@ static int mp3_decode(void)
if (err) {
if (err == ERR_MP3_MAINDATA_UNDERFLOW && !had_err) {
// just need another frame
mp3_file_pos += readPtr - mp3_input_buffer;
*file_pos += readPtr - mp3_input_buffer;
continue;
}
if (err == ERR_MP3_INDATA_UNDERFLOW && !had_err) {
if (offset == 0)
// something's really wrong here, frame had to fit
mp3_file_pos = mp3_file_len;
*file_pos = file_len;
else
mp3_file_pos += offset;
*file_pos += offset;
continue;
}
if (-12 <= err && err <= -6) {
// ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*
// just try to skip the offending frame..
mp3_file_pos += offset + 1;
*file_pos += offset + 1;
continue;
}
lprintf("MP3Decode err (%i/%i) %i\n", mp3_file_pos, mp3_file_len, err);
mp3_file_pos = mp3_file_len;
lprintf("MP3Decode err (%i/%i) %i\n",
*file_pos, file_len, err);
*file_pos = file_len;
return 1;
}
mp3_file_pos += readPtr - mp3_input_buffer;
*file_pos += readPtr - mp3_input_buffer;
}
while (0);
return 0;
}
void mp3_start_play(void *f_, int pos)
int mp3dec_start(void)
{
FILE *f = f_;
mp3_file_len = mp3_file_pos = 0;
mp3_current_file = NULL;
mp3_buffer_offs = 0;
if (!(PicoOpt & POPT_EN_MCD_CDDA) || f == NULL) // cdda disabled or no file?
return;
// must re-init decoder for new track
if (mp3dec)
MP3FreeDecoder(mp3dec);
mp3dec = MP3InitDecoder();
mp3_current_file = f;
fseek(f, 0, SEEK_END);
mp3_file_len = ftell(f);
// search for first sync word, skipping stuff like ID3 tags
while (mp3_file_pos < 128*1024) {
int offs, bytes;
fseek(f, mp3_file_pos, SEEK_SET);
bytes = fread(mp3_input_buffer, 1, sizeof(mp3_input_buffer), f);
if (bytes < 4)
break;
offs = mp3_find_sync_word(mp3_input_buffer, bytes);
if (offs >= 0) {
mp3_file_pos += offs;
break;
}
mp3_file_pos += bytes - 2;
}
// seek..
if (pos) {
unsigned long long pos64 = mp3_file_len - mp3_file_pos;
pos64 *= pos;
mp3_file_pos += pos64 >> 10;
}
mp3_decode();
return (mp3dec == 0) ? -1 : 0;
}
void mp3_update(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;
if (mp3_current_file == NULL || mp3_file_pos >= mp3_file_len)
return; /* no file / EOF */
length_mp3 = length;
if (PsndRate <= 11025 + 100) {
mix_samples = mix_16h_to_32_s2;
length_mp3 <<= 2; shr = 2;
}
else if (PsndRate <= 22050 + 100) {
mix_samples = mix_16h_to_32_s1;
length_mp3 <<= 1; shr = 1;
}
if (1152 - mp3_buffer_offs >= length_mp3) {
mix_samples(buffer, cdda_out_buffer + mp3_buffer_offs*2, length<<1);
mp3_buffer_offs += length_mp3;
} else {
int ret, left = 1152 - mp3_buffer_offs;
mix_samples(buffer, cdda_out_buffer + mp3_buffer_offs*2, (left>>shr)<<1);
ret = mp3_decode();
if (ret == 0) {
mp3_buffer_offs = length_mp3 - left;
mix_samples(buffer + ((left>>shr)<<1), cdda_out_buffer, (mp3_buffer_offs>>shr)<<1);
} else
mp3_buffer_offs = 0;
}
}