X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=platform%2Fcommon%2Fmp3_helix.c;fp=platform%2Fcommon%2Fmp3_helix.c;h=a5da3761eadddd3a90bc15f78b0b7cb8e3fd24e5;hb=da42200b24749eee63cccf49d87781b861146e9f;hp=0000000000000000000000000000000000000000;hpb=a8869ad1e809e6cacd6141fa7e9c86d349b0c0be;p=picodrive.git diff --git a/platform/common/mp3_helix.c b/platform/common/mp3_helix.c new file mode 100644 index 0000000..a5da376 --- /dev/null +++ b/platform/common/mp3_helix.c @@ -0,0 +1,251 @@ +// Some mp3 related code for Sega/Mega CD. +// Uses the Helix Fixed-point MP3 decoder + +// (c) Copyright 2007, Grazvydas "notaz" Ignotas + +#include +#include + +#include "../../Pico/PicoInt.h" +#include "../../Pico/sound/mix.h" +#include "helix/pub/mp3dec.h" +#include "lprintf.h" + +static short mp3_out_buffer[2*1152]; +static HMP3Decoder mp3dec = 0; +static int mp3_buffer_offs = 0; + + +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; +} + + +#ifdef __GP2X__ + +#include "../gp2x/code940/940shared.h" + +extern _940_ctl_t *shared_ctl; +extern unsigned char *mp3_mem; + +static int 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 1; // EOF, nothing to do + + offset = MP3FindSyncWord(readPtr, bytesLeft); + if (offset < 0) { + shared_ctl->mp3_offs = shared_ctl->mp3_len; + return 1; // 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 1; + } 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; + return 0; +} + +void mp3_start_local(void) +{ + mp3_buffer_offs = 0; + mp3_decode(); +} + +#define mp3_update mp3_update_local + +#else + +static FILE *mp3_current_file = NULL; +static int mp3_file_len = 0, mp3_file_pos = 0; +static unsigned char mp3_input_buffer[2*1024]; + +static int mp3_decode(void) +{ + unsigned char *readPtr; + int bytesLeft; + int offset; // mp3 frame offset from readPtr + int err; + + do + { + if (mp3_file_pos >= mp3_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); + + offset = MP3FindSyncWord(mp3_input_buffer, bytesLeft); + if (offset < 0) { + //lprintf("MP3FindSyncWord (%i/%i) err %i\n", mp3_file_pos, mp3_file_len, offset); + mp3_file_pos = mp3_file_len; + return 1; // EOF + } + readPtr = mp3_input_buffer + offset; + bytesLeft -= offset; + + err = MP3Decode(mp3dec, &readPtr, &bytesLeft, mp3_out_buffer, 0); + if (err) { + //lprintf("MP3Decode err (%i/%i) %i\n", mp3_file_pos, mp3_file_len, err); + if (err == ERR_MP3_INDATA_UNDERFLOW) { + if (offset == 0) + // something's really wrong here, frame had to fit + mp3_file_pos = mp3_file_len; + else + mp3_file_pos += offset; + continue; + } else if (err <= -6 && err >= -12) { + // ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_* + // just try to skip the offending frame.. + mp3_file_pos += offset + 1; + continue; + } + mp3_file_pos = mp3_file_len; + return 1; + } + mp3_file_pos += readPtr - mp3_input_buffer; + } + while (0); + + return 0; +} + +void mp3_start_play(FILE *f, int pos) +{ + mp3_file_len = mp3_file_pos = 0; + mp3_current_file = NULL; + mp3_buffer_offs = 0; + + if (!(PicoOpt&0x800) || f == NULL) // cdda disabled or no file? + return; + + //lprintf("mp3_start_play %p %i\n", f, pos); + + mp3_current_file = f; + fseek(f, 0, SEEK_END); + mp3_file_len = ftell(f); + + // seek.. + if (pos) { + mp3_file_pos = (mp3_file_len << 6) >> 10; + mp3_file_pos *= pos; + mp3_file_pos >>= 6; + } + + mp3_decode(); +} + +int mp3_get_offset(void) +{ + unsigned int offs1024 = 0; + int cdda_on; + + cdda_on = (PicoMCD & 1) && (PicoOpt&0x800) && !(Pico_mcd->s68k_regs[0x36] & 1) && + (Pico_mcd->scd.Status_CDC & 1) && mp3_current_file != NULL; + + if (cdda_on) { + offs1024 = mp3_file_pos << 7; + offs1024 /= mp3_file_len >> 3; + } + //lprintf("mp3_get_offset offs1024=%u (%i/%i)\n", offs1024, mp3_file_pos, mp3_file_len); + + return offs1024; +} + +#endif // ifndef __GP2X__ + +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; + +#ifndef __GP2X__ + if (mp3_current_file == NULL || mp3_file_pos >= mp3_file_len) return; // no file / EOF +#endif + + 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 ret, left = 1152 - mp3_buffer_offs; + + mix_samples(buffer, mp3_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), mp3_out_buffer, (mp3_buffer_offs>>shr)<<1); + } else + mp3_buffer_offs = 0; + } +} + +