occasional mp3 click noises fixed

[picodrive.git] / platform / gp2x / code940 / 940.c

diff --git a/platform/gp2x/code940/940.c b/platform/gp2x/code940/940.c
index 0df1945..90087a3 100644 (file)
--- a/platform/gp2x/code940/940.c
+++ b/platform/gp2x/code940/940.c
@@ -25,17 +25,44 @@ void _memcpy(void *dst, const void *src, int count);
 //     asm volatile ("mcr p15, 0, r0, c7, c10, 4" ::: "r0"); /* drain write buffer */\r
 \r
 \r
+static int find_sync_word(unsigned char *buf, int nBytes)\r
+{\r
+       unsigned char *p, *pe;\r
+\r
+       /* find byte-aligned syncword - need 12 (MPEG 1,2) or 11 (MPEG 2.5) matching bits */\r
+       for (p = buf, pe = buf + nBytes - 4; p < pe; p++)\r
+       {\r
+               int pn;\r
+               if (p[0] != 0xff) continue;\r
+               pn = p[1];\r
+               if ((pn & 0xf8) != 0xf8 || // currently must be MPEG1\r
+                   (pn & 6) == 0) {       // invalid layer\r
+                       p++; continue;\r
+               }\r
+               pn = p[2];\r
+               if ((pn & 0xf0) < 0x20 || (pn & 0xf0) == 0xf0 || // bitrates\r
+                   (pn & 0x0c) != 0) { // not 44kHz\r
+                       continue;\r
+               }\r
+\r
+               return p - buf;\r
+       }\r
+\r
+       return -1;\r
+}\r
+\r
 static void mp3_decode(void)\r
 {\r
        int mp3_offs = shared_ctl->mp3_offs;\r
        unsigned char *readPtr = mp3_data + mp3_offs;\r
        int bytesLeft = shared_ctl->mp3_len - mp3_offs;\r
        int offset; // frame offset from readPtr\r
-       int err;\r
+       int retries = 0, err;\r
 \r
        if (bytesLeft <= 0) return; // EOF, nothing to do\r
 \r
-       offset = MP3FindSyncWord(readPtr, bytesLeft);\r
+retry:\r
+       offset = find_sync_word(readPtr, bytesLeft);\r
        if (offset < 0) {\r
                set_if_not_changed(&shared_ctl->mp3_offs, mp3_offs, shared_ctl->mp3_len);\r
                return; // EOF\r
@@ -53,6 +80,8 @@ static void mp3_decode(void)
                        // ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*\r
                        // just try to skip the offending frame..\r
                        readPtr++;\r
+                       bytesLeft--;\r
+                       if (retries++ < 2) goto retry;\r
                }\r
                shared_ctl->mp3_errors++;\r
                shared_ctl->mp3_lasterr = err;\r
@@ -189,6 +218,11 @@ void Main940(void)
                        case JOB940_MP3DECODE:\r
                                mp3_decode();\r
                                break;\r
+\r
+                       case JOB940_MP3RESET:\r
+                               if (shared_data->mp3dec) MP3FreeDecoder(shared_data->mp3dec);\r
+                               shared_data->mp3dec = MP3InitDecoder();\r
+                               break;\r
                }\r
 \r
                shared_ctl->loopc++;\r