mlpdec: Allocate channel decoding parameters for each substream. Some file

was encountered with a channel range that overlapped the previous substreams,
and the code assumed no such overlap was possible.
Patch by Nick Brereton <nick at nbrereton dot net>

Originally committed as revision 23084 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/mlpdec.c

@@ -62,6 +62,8 @@ typedef struct SubStream {
     //! For each channel output by the matrix, the output channel to map it to
     uint8_t     ch_assign[MAX_CHANNELS];
 
+    ChannelParams channel_params[MAX_CHANNELS];
+
     //! The left shift applied to random noise in 0x31ea substreams.
     uint8_t     noise_shift;
     //! The current seed value for the pseudorandom noise generator(s).
@@ -137,8 +139,6 @@ typedef struct MLPDecodeContext {
 
     SubStream   substream[MAX_SUBSTREAMS];
 
-    ChannelParams channel_params[MAX_CHANNELS];
-
     int         matrix_changed;
     int         filter_changed[MAX_CHANNELS][NUM_FILTERS];
 
@@ -173,8 +173,8 @@ static av_cold void init_static(void)
 static inline int32_t calculate_sign_huff(MLPDecodeContext *m,
                                           unsigned int substr, unsigned int ch)
 {
-    ChannelParams *cp = &m->channel_params[ch];
     SubStream *s = &m->substream[substr];
+    ChannelParams *cp = &s->channel_params[ch];
     int lsb_bits = cp->huff_lsbs - s->quant_step_size[ch];
     int sign_shift = lsb_bits + (cp->codebook ? 2 - cp->codebook : -1);
     int32_t sign_huff_offset = cp->huff_offset;
@@ -202,7 +202,7 @@ static inline int read_huff_channels(MLPDecodeContext *m, GetBitContext *gbp,
             m->bypassed_lsbs[pos + s->blockpos][mat] = get_bits1(gbp);
 
     for (channel = s->min_channel; channel <= s->max_channel; channel++) {
-        ChannelParams *cp = &m->channel_params[channel];
+        ChannelParams *cp = &s->channel_params[channel];
         int codebook = cp->codebook;
         int quant_step_size = s->quant_step_size[channel];
         int lsb_bits = cp->huff_lsbs - quant_step_size;
@@ -450,7 +450,7 @@ static int read_restart_header(MLPDecodeContext *m, GetBitContext *gbp,
     memset(s->quant_step_size, 0, sizeof(s->quant_step_size));
 
     for (ch = s->min_channel; ch <= s->max_channel; ch++) {
-        ChannelParams *cp = &m->channel_params[ch];
+        ChannelParams *cp = &s->channel_params[ch];
         cp->filter_params[FIR].order = 0;
         cp->filter_params[IIR].order = 0;
         cp->filter_params[FIR].shift = 0;
@@ -472,9 +472,11 @@ static int read_restart_header(MLPDecodeContext *m, GetBitContext *gbp,
 /** Read parameters for one of the prediction filters. */
 
 static int read_filter_params(MLPDecodeContext *m, GetBitContext *gbp,
-                              unsigned int channel, unsigned int filter)
+                              unsigned int substr, unsigned int channel,
+                              unsigned int filter)
 {
-    FilterParams *fp = &m->channel_params[channel].filter_params[filter];
+    SubStream *s = &m->substream[substr];
+    FilterParams *fp = &s->channel_params[channel].filter_params[filter];
     const int max_order = filter ? MAX_IIR_ORDER : MAX_FIR_ORDER;
     const char fchar = filter ? 'I' : 'F';
     int i, order;
@@ -497,7 +499,7 @@ static int read_filter_params(MLPDecodeContext *m, GetBitContext *gbp,
     fp->order = order;
 
     if (order > 0) {
-        int32_t *fcoeff = m->channel_params[channel].coeff[filter];
+        int32_t *fcoeff = s->channel_params[channel].coeff[filter];
         int coeff_bits, coeff_shift;
 
         fp->shift = get_bits(gbp, 4);
@@ -610,19 +612,19 @@ static int read_matrix_params(MLPDecodeContext *m, unsigned int substr, GetBitCo
 static int read_channel_params(MLPDecodeContext *m, unsigned int substr,
                                GetBitContext *gbp, unsigned int ch)
 {
-    ChannelParams *cp = &m->channel_params[ch];
+    SubStream *s = &m->substream[substr];
+    ChannelParams *cp = &s->channel_params[ch];
     FilterParams *fir = &cp->filter_params[FIR];
     FilterParams *iir = &cp->filter_params[IIR];
-    SubStream *s = &m->substream[substr];
 
     if (s->param_presence_flags & PARAM_FIR)
         if (get_bits1(gbp))
-            if (read_filter_params(m, gbp, ch, FIR) < 0)
+            if (read_filter_params(m, gbp, substr, ch, FIR) < 0)
                 return -1;
 
     if (s->param_presence_flags & PARAM_IIR)
         if (get_bits1(gbp))
-            if (read_filter_params(m, gbp, ch, IIR) < 0)
+            if (read_filter_params(m, gbp, substr, ch, IIR) < 0)
                 return -1;
 
     if (fir->order + iir->order > 8) {
@@ -697,7 +699,7 @@ static int read_decoding_params(MLPDecodeContext *m, GetBitContext *gbp,
     if (s->param_presence_flags & PARAM_QUANTSTEP)
         if (get_bits1(gbp))
             for (ch = 0; ch <= s->max_channel; ch++) {
-                ChannelParams *cp = &m->channel_params[ch];
+                ChannelParams *cp = &s->channel_params[ch];
 
                 s->quant_step_size[ch] = get_bits(gbp, 4);
 
@@ -721,12 +723,12 @@ static void filter_channel(MLPDecodeContext *m, unsigned int substr,
                            unsigned int channel)
 {
     SubStream *s = &m->substream[substr];
-    const int32_t *fircoeff = m->channel_params[channel].coeff[FIR];
+    const int32_t *fircoeff = s->channel_params[channel].coeff[FIR];
     int32_t state_buffer[NUM_FILTERS][MAX_BLOCKSIZE + MAX_FIR_ORDER];
     int32_t *firbuf = state_buffer[FIR] + MAX_BLOCKSIZE;
     int32_t *iirbuf = state_buffer[IIR] + MAX_BLOCKSIZE;
-    FilterParams *fir = &m->channel_params[channel].filter_params[FIR];
-    FilterParams *iir = &m->channel_params[channel].filter_params[IIR];
+    FilterParams *fir = &s->channel_params[channel].filter_params[FIR];
+    FilterParams *iir = &s->channel_params[channel].filter_params[IIR];
     unsigned int filter_shift = fir->shift;
     int32_t mask = MSB_MASK(s->quant_step_size[channel]);