move more globals to PicoInterface

[picodrive.git] / platform / common / mp3.c

diff --git a/platform/common/mp3.c b/platform/common/mp3.c
index b00a5fb..c84962c 100644 (file)
--- a/platform/common/mp3.c
+++ b/platform/common/mp3.c
@@ -1,5 +1,26 @@
+/*
+ * PicoDrive
+ * (C) notaz, 2010,2013
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
+#include <stdio.h>
+#include <string.h>
+
+#include <pico/pico_int.h>
+#include <pico/sound/mix.h>
 #include "mp3.h"
 
+static FILE *mp3_current_file;
+static int mp3_file_len, mp3_file_pos;
+static int cdda_out_pos;
+static int decoder_active;
+
+unsigned short mpeg1_l3_bitrates[16] = {
+       0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320
+};
+
 int mp3_find_sync_word(const unsigned char *buf, int size)
 {
        const unsigned char *p, *pe;
@@ -27,3 +48,155 @@ int mp3_find_sync_word(const unsigned char *buf, int size)
        return -1;
 }
 
+static int try_get_bitrate(unsigned char *buf, int buf_size)
+{
+       int offs1, offs = 0;
+       int ret;
+
+       while (1)
+       {
+               offs1 = mp3_find_sync_word(buf + offs, buf_size - offs);
+               if (offs1 < 0)
+                       return -2;
+               offs += offs1;
+               if (buf_size - offs < 4)
+                       return -3;
+
+               // printf("trying header %08x\n", *(int *)(buf + offs));
+
+               ret = mpeg1_l3_bitrates[buf[offs + 2] >> 4];
+               if (ret > 0)
+                       return ret;
+       }
+
+       return -2;
+}
+
+int mp3_get_bitrate(void *f_, int len)
+{
+       unsigned char buf[2048];
+       FILE *f = f_;
+       int retval = -1;
+       int ret;
+
+       memset(buf, 0, sizeof(buf));
+
+       fseek(f, 0, SEEK_SET);
+       ret = fread(buf, 1, sizeof(buf), f);
+       if (ret != sizeof(buf))
+               goto out;
+
+       ret = try_get_bitrate(buf, sizeof(buf));
+       if (ret <= 0) {
+               // try to read somewhere around the middle
+               fseek(f, len / 2, SEEK_SET);
+               ret = fread(buf, 1, sizeof(buf), f);
+               if (ret == sizeof(buf))
+                       ret = try_get_bitrate(buf, sizeof(buf));
+       }
+       if (ret > 0)
+               retval = ret;
+
+       //printf("bitrate: %i\n", retval);
+
+out:
+       fseek(f, 0, SEEK_SET);
+       return retval;
+}
+
+void mp3_start_play(void *f_, int pos1024)
+{
+       unsigned char buf[2048];
+       FILE *f = f_;
+       int ret;
+
+       mp3_file_len = mp3_file_pos = 0;
+       mp3_current_file = NULL;
+       cdda_out_pos = 0;
+       decoder_active = 0;
+
+       if (!(PicoIn.opt & POPT_EN_MCD_CDDA) || f == NULL) // cdda disabled or no file?
+               return;
+
+       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(buf, 1, sizeof(buf), f);
+               if (bytes < 4)
+                       break;
+               offs = mp3_find_sync_word(buf, bytes);
+               if (offs >= 0) {
+                       mp3_file_pos += offs;
+                       break;
+               }
+               mp3_file_pos += bytes - 3;
+       }
+
+       // seek..
+       if (pos1024 != 0) {
+               unsigned long long pos64 = mp3_file_len - mp3_file_pos;
+               pos64 *= pos1024;
+               mp3_file_pos += pos64 >> 10;
+       }
+
+       ret = mp3dec_start(f, mp3_file_pos);
+       if (ret != 0) {
+               return;
+       }
+
+       mp3_current_file = f;
+       decoder_active = 1;
+
+       mp3dec_decode(mp3_current_file, &mp3_file_pos, mp3_file_len);
+}
+
+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 */
+
+       if (!decoder_active)
+               return;
+
+       length_mp3 = length;
+       if (PicoIn.sndRate <= 11025 + 100) {
+               mix_samples = mix_16h_to_32_s2;
+               length_mp3 <<= 2; shr = 2;
+       }
+       else if (PicoIn.sndRate <= 22050 + 100) {
+               mix_samples = mix_16h_to_32_s1;
+               length_mp3 <<= 1; shr = 1;
+       }
+
+       if (1152 - cdda_out_pos >= length_mp3) {
+               mix_samples(buffer, cdda_out_buffer + cdda_out_pos * 2,
+                       length * 2);
+
+               cdda_out_pos += length_mp3;
+       } else {
+               int ret, left = 1152 - cdda_out_pos;
+
+               if (left > 0)
+                       mix_samples(buffer, cdda_out_buffer + cdda_out_pos * 2,
+                               (left >> shr) * 2);
+
+               ret = mp3dec_decode(mp3_current_file, &mp3_file_pos,
+                       mp3_file_len);
+               if (ret == 0) {
+                       cdda_out_pos = length_mp3 - left;
+                       mix_samples(buffer + (left >> shr) * 2,
+                               cdda_out_buffer,
+                               (cdda_out_pos >> shr) * 2);
+               } else
+                       cdda_out_pos = 0;
+       }
+}
+