avcodec/mqcdec: Support raw bypass and non reseting init

Some broken code that used the old mqc is removed
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/jpeg2000dec.c

@@ -1135,7 +1135,7 @@ static int decode_cblk(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *codsty,
 
     cblk->data[cblk->length] = 0xff;
     cblk->data[cblk->length+1] = 0xff;
-    ff_mqc_initdec(&t1->mqc, cblk->data);
+    ff_mqc_initdec(&t1->mqc, cblk->data, 0, 1);
 
     while (passno--) {
         switch(pass_t) {
@@ -1146,16 +1146,11 @@ static int decode_cblk(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *codsty,
             break;
         case 1:
             decode_refpass(t1, width, height, bpno + 1);
-            if (bpass_csty_symbol && clnpass_cnt >= 4)
-                ff_mqc_initdec(&t1->mqc, cblk->data);
             break;
         case 2:
             decode_clnpass(s, t1, width, height, bpno + 1, bandpos,
                            codsty->cblk_style & JPEG2000_CBLK_SEGSYM,
                            vert_causal_ctx_csty_symbol);
-            clnpass_cnt = clnpass_cnt + 1;
-            if (bpass_csty_symbol && clnpass_cnt >= 4)
-                ff_mqc_initdec(&t1->mqc, cblk->data);
             break;
         }
 

libavcodec/mqc.h

@@ -43,6 +43,7 @@ typedef struct MqcState {
     unsigned int c;
     unsigned int ct;
     uint8_t cx_states[19];
+    int raw;
 } MqcState;
 
 /* encoder */
@@ -65,8 +66,10 @@ int ff_mqc_flush(MqcState *mqc);
  * Initialize MQ-decoder.
  * @param mqc   MQ decoder state
  * @param bp    byte poiter
+ * @param raw   raw mode
+ * @param reset reset states
  */
-void ff_mqc_initdec(MqcState *mqc, uint8_t *bp);
+void ff_mqc_initdec(MqcState *mqc, uint8_t *bp, int raw, int reset);
 
 /**
  * MQ decoder.

libavcodec/mqcdec.c

@@ -68,18 +68,32 @@ static int exchange(MqcState *mqc, uint8_t *cxstate, int lps)
     return d;
 }
 
-void ff_mqc_initdec(MqcState *mqc, uint8_t *bp)
+void ff_mqc_initdec(MqcState *mqc, uint8_t *bp, int raw, int reset)
 {
-    ff_mqc_init_contexts(mqc);
+    if (reset)
+        ff_mqc_init_contexts(mqc);
     mqc->bp = bp;
     mqc->c  = (*mqc->bp ^ 0xff) << 16;
     bytein(mqc);
     mqc->c = mqc->c << 7;
     mqc->a = 0x8000;
+    mqc->raw = raw;
+}
+
+static int mqc_decode_bypass(MqcState *mqc) {
+    int bit = !(mqc->c & 0x40000000);
+    if (!(mqc->c & 0xff)) {
+        mqc->c -= 0x100;
+        bytein(mqc);
+    }
+    mqc->c += mqc->c;
+    return bit;
 }
 
 int ff_mqc_decode(MqcState *mqc, uint8_t *cxstate)
 {
+    if (mqc->raw)
+        return mqc_decode_bypass(mqc);
     mqc->a -= ff_mqc_qe[*cxstate];
     if ((mqc->c >> 16) < mqc->a) {
         if (mqc->a & 0x8000)