avcodec/snow: gray support

Fixes Ticket839

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 30 insertions, 16 deletions

diff --git a/libavcodec/snowdec.c b/libavcodec/snowdec.c
index 8da2f17ffb..8bd4dc19c9 100644
--- a/libavcodec/snowdec.c
+++ b/libavcodec/snowdec.c
@@ -163,8 +163,10 @@ static int decode_q_branch(SnowContext *s, int level, int x, int y){
         if(type){
             pred_mv(s, &mx, &my, 0, left, top, tr);
             l += get_symbol(&s->c, &s->block_state[32], 1);
-            cb+= get_symbol(&s->c, &s->block_state[64], 1);
-            cr+= get_symbol(&s->c, &s->block_state[96], 1);
+            if (s->nb_planes > 2) {
+                cb+= get_symbol(&s->c, &s->block_state[64], 1);
+                cr+= get_symbol(&s->c, &s->block_state[96], 1);
+            }
         }else{
             if(s->ref_frames > 1)
                 ref= get_symbol(&s->c, &s->block_state[128 + 1024 + 32*ref_context], 0);
@@ -243,7 +245,7 @@ static void correlate_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand
 static void decode_qlogs(SnowContext *s){
     int plane_index, level, orientation;
 
-    for(plane_index=0; plane_index<3; plane_index++){
+    for(plane_index=0; plane_index < s->nb_planes; plane_index++){
         for(level=0; level<s->spatial_decomposition_count; level++){
             for(orientation=level ? 1:0; orientation<4; orientation++){
                 int q;
@@ -286,22 +288,34 @@ static int decode_header(SnowContext *s){
         s->temporal_decomposition_count= get_symbol(&s->c, s->header_state, 0);
         GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)
         s->colorspace_type= get_symbol(&s->c, s->header_state, 0);
-        s->chroma_h_shift= get_symbol(&s->c, s->header_state, 0);
-        s->chroma_v_shift= get_symbol(&s->c, s->header_state, 0);
-
-        if(s->chroma_h_shift == 1 && s->chroma_v_shift==1){
-            s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
-        }else if(s->chroma_h_shift == 0 && s->chroma_v_shift==0){
-            s->avctx->pix_fmt= AV_PIX_FMT_YUV444P;
-        }else if(s->chroma_h_shift == 2 && s->chroma_v_shift==2){
-            s->avctx->pix_fmt= AV_PIX_FMT_YUV410P;
+        if (s->colorspace_type == 1) {
+            s->avctx->pix_fmt= AV_PIX_FMT_GRAY8;
+            s->nb_planes = 1;
+        } else if(s->colorspace_type == 0) {
+            s->chroma_h_shift= get_symbol(&s->c, s->header_state, 0);
+            s->chroma_v_shift= get_symbol(&s->c, s->header_state, 0);
+
+            if(s->chroma_h_shift == 1 && s->chroma_v_shift==1){
+                s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
+            }else if(s->chroma_h_shift == 0 && s->chroma_v_shift==0){
+                s->avctx->pix_fmt= AV_PIX_FMT_YUV444P;
+            }else if(s->chroma_h_shift == 2 && s->chroma_v_shift==2){
+                s->avctx->pix_fmt= AV_PIX_FMT_YUV410P;
+            } else {
+                av_log(s, AV_LOG_ERROR, "unsupported color subsample mode %d %d\n", s->chroma_h_shift, s->chroma_v_shift);
+                s->chroma_h_shift = s->chroma_v_shift = 1;
+                s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
+                return AVERROR_INVALIDDATA;
+            }
+            s->nb_planes = 3;
         } else {
-            av_log(s, AV_LOG_ERROR, "unsupported color subsample mode %d %d\n", s->chroma_h_shift, s->chroma_v_shift);
+            av_log(s, AV_LOG_ERROR, "unsupported color space\n");
             s->chroma_h_shift = s->chroma_v_shift = 1;
             s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
             return AVERROR_INVALIDDATA;
         }
 
+
         s->spatial_scalability= get_rac(&s->c, s->header_state);
 //        s->rate_scalability= get_rac(&s->c, s->header_state);
         GET_S(s->max_ref_frames, tmp < (unsigned)MAX_REF_FRAMES)
@@ -312,7 +326,7 @@ static int decode_header(SnowContext *s){
 
     if(!s->keyframe){
         if(get_rac(&s->c, s->header_state)){
-            for(plane_index=0; plane_index<2; plane_index++){
+            for(plane_index=0; plane_index<FFMIN(s->nb_planes, 2); plane_index++){
                 int htaps, i, sum=0;
                 Plane *p= &s->plane[plane_index];
                 p->diag_mc= get_rac(&s->c, s->header_state);
@@ -418,7 +432,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
                                     s->spatial_idwt_buffer)) < 0)
         return res;
 
-    for(plane_index=0; plane_index<3; plane_index++){
+    for(plane_index=0; plane_index < s->nb_planes; plane_index++){
         Plane *p= &s->plane[plane_index];
         p->fast_mc= p->diag_mc && p->htaps==6 && p->hcoeff[0]==40
                                               && p->hcoeff[1]==-10
@@ -436,7 +450,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
     if ((res = decode_blocks(s)) < 0)
         return res;
 
-    for(plane_index=0; plane_index<3; plane_index++){
+    for(plane_index=0; plane_index < s->nb_planes; plane_index++){
         Plane *p= &s->plane[plane_index];
         int w= p->width;
         int h= p->height;