X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=platform%2Fgp2x%2Fcode940%2F940.c;h=a4d3a464d8a0549e9d6ded3473f0176f764bf94b;hb=1f1ff763e661bab664151c4821c65dad35777976;hp=0df19453db952452f7a61cc2f54f8954413e7984;hpb=e4fb433cd685d06ddbf0ec367c19a38b75d6ac68;p=picodrive.git

diff --git a/platform/gp2x/code940/940.c b/platform/gp2x/code940/940.c
index 0df1945..a4d3a46 100644
--- a/platform/gp2x/code940/940.c
+++ b/platform/gp2x/code940/940.c
@@ -25,39 +25,79 @@ void _memcpy(void *dst, const void *src, int count);
 //	asm volatile ("mcr p15, 0, r0, c7, c10, 4" ::: "r0"); /* drain write buffer */
 
 
+static int find_sync_word(unsigned char *buf, int nBytes)
+{
+	unsigned char *p, *pe;
+
+	/* find byte-aligned syncword - need 12 (MPEG 1,2) or 11 (MPEG 2.5) matching bits */
+	for (p = buf, pe = buf + nBytes - 4; p < pe; p++)
+	{
+		int pn;
+		if (p[0] != 0xff) continue;
+		pn = p[1];
+		if ((pn & 0xf8) != 0xf8 || // currently must be MPEG1
+		    (pn & 6) == 0) {       // invalid layer
+			p++; continue;
+		}
+		pn = p[2];
+		if ((pn & 0xf0) < 0x20 || (pn & 0xf0) == 0xf0 || // bitrates
+		    (pn & 0x0c) != 0) { // not 44kHz
+			continue;
+		}
+
+		return p - buf;
+	}
+
+	return -1;
+}
+
 static void mp3_decode(void)
 {
 	int mp3_offs = shared_ctl->mp3_offs;
 	unsigned char *readPtr = mp3_data + mp3_offs;
 	int bytesLeft = shared_ctl->mp3_len - mp3_offs;
 	int offset; // frame offset from readPtr
-	int err;
+	int retries = 0, err;
 
 	if (bytesLeft <= 0) return; // EOF, nothing to do
 
-	offset = MP3FindSyncWord(readPtr, bytesLeft);
-	if (offset < 0) {
-		set_if_not_changed(&shared_ctl->mp3_offs, mp3_offs, shared_ctl->mp3_len);
-		return; // EOF
-	}
-	readPtr += offset;
-	bytesLeft -= offset;
-
-	err = MP3Decode(shared_data->mp3dec, &readPtr, &bytesLeft,
-			shared_data->mp3_buffer[shared_ctl->mp3_buffsel], 0);
-	if (err) {
-		if (err == ERR_MP3_INDATA_UNDERFLOW) {
-			set_if_not_changed(&shared_ctl->mp3_offs, mp3_offs, shared_ctl->mp3_len);
-			return;
-		} else if (err <= -6 && err >= -12) {
-			// ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*
-			// just try to skip the offending frame..
-			readPtr++;
+	for (retries = 0; retries < 2; retries++)
+	{
+		offset = find_sync_word(readPtr, bytesLeft);
+		if (offset < 0)
+			goto set_eof;
+
+		readPtr += offset;
+		bytesLeft -= offset;
+
+		err = MP3Decode(shared_data->mp3dec, &readPtr, &bytesLeft,
+				shared_data->mp3_buffer[shared_ctl->mp3_buffsel], 0);
+		if (err) {
+			if (err == ERR_MP3_MAINDATA_UNDERFLOW)
+				// just need another frame
+				continue;
+
+			if (err == ERR_MP3_INDATA_UNDERFLOW)
+				goto set_eof;
+
+			if (err <= -6 && err >= -12) {
+				// ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*
+				// just try to skip the offending frame..
+				readPtr++;
+				bytesLeft--;
+				continue;
+			}
+			shared_ctl->mp3_errors++;
+			shared_ctl->mp3_lasterr = err;
 		}
-		shared_ctl->mp3_errors++;
-		shared_ctl->mp3_lasterr = err;
+		break;
 	}
+
 	set_if_not_changed(&shared_ctl->mp3_offs, mp3_offs, readPtr - mp3_data);
+	return;
+
+set_eof:
+	set_if_not_changed(&shared_ctl->mp3_offs, mp3_offs, shared_ctl->mp3_len);
 }
 
 static void ym_flush_writes(void)
@@ -189,6 +229,11 @@ void Main940(void)
 			case JOB940_MP3DECODE:
 				mp3_decode();
 				break;
+
+			case JOB940_MP3RESET:
+				if (shared_data->mp3dec) MP3FreeDecoder(shared_data->mp3dec);
+				shared_data->mp3dec = MP3InitDecoder();
+				break;
 		}
 
 		shared_ctl->loopc++;