ffv1enc: Store transparency plane.

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

libavcodec/ffv1.c

@@ -165,6 +165,7 @@ typedef struct FFV1Context{
     int version;
     int width, height;
     int chroma_h_shift, chroma_v_shift;
+    int transparency;
     int flags;
     int picture_number;
     AVFrame picture;
@@ -562,21 +563,22 @@ static void encode_plane(FFV1Context *s, uint8_t *src, int w, int h, int stride,
 static void encode_rgb_frame(FFV1Context *s, uint32_t *src, int w, int h, int stride){
     int x, y, p, i;
     const int ring_size= s->avctx->context_model ? 3 : 2;
-    int16_t *sample[3][3];
+    int16_t *sample[4][3];
     s->run_index=0;
 
-    memset(s->sample_buffer, 0, ring_size*3*(w+6)*sizeof(*s->sample_buffer));
+    memset(s->sample_buffer, 0, ring_size*4*(w+6)*sizeof(*s->sample_buffer));
 
     for(y=0; y<h; y++){
         for(i=0; i<ring_size; i++)
-            for(p=0; p<3; p++)
+            for(p=0; p<4; p++)
                 sample[p][i]= s->sample_buffer + p*ring_size*(w+6) + ((h+i-y)%ring_size)*(w+6) + 3;
 
         for(x=0; x<w; x++){
-            int v= src[x + stride*y];
+            unsigned v= src[x + stride*y];
             int b= v&0xFF;
             int g= (v>>8)&0xFF;
             int r= (v>>16)&0xFF;
+            int a=  v>>24;
 
             b -= g;
             r -= g;
@@ -589,11 +591,12 @@ static void encode_rgb_frame(FFV1Context *s, uint32_t *src, int w, int h, int st
             sample[0][0][x]= g;
             sample[1][0][x]= b;
             sample[2][0][x]= r;
+            sample[3][0][x]= a;
         }
-        for(p=0; p<3; p++){
+        for(p=0; p<4; p++){
             sample[p][0][-1]= sample[p][1][0  ];
             sample[p][1][ w]= sample[p][1][w-1];
-            encode_line(s, w, sample[p], FFMIN(p, 1), 9);
+            encode_line(s, w, sample[p], (p+1)/2, 9);
         }
     }
 }
@@ -640,7 +643,7 @@ static void write_header(FFV1Context *f){
         put_rac(c, state, 1); //chroma planes
             put_symbol(c, state, f->chroma_h_shift, 0);
             put_symbol(c, state, f->chroma_v_shift, 0);
-        put_rac(c, state, 0); //no transparency plane
+        put_rac(c, state, f->transparency);
 
         write_quant_tables(c, f->quant_table);
     }else{
@@ -687,6 +690,8 @@ static int init_slice_state(FFV1Context *f){
 
     for(i=0; i<f->slice_count; i++){
         FFV1Context *fs= f->slice_context[i];
+        fs->plane_count= f->plane_count;
+        fs->transparency= f->transparency;
         for(j=0; j<f->plane_count; j++){
             PlaneContext * const p= &fs->plane[j];
 
@@ -735,7 +740,7 @@ static av_cold int init_slice_contexts(FFV1Context *f){
         fs->slice_x     = sxs;
         fs->slice_y     = sys;
 
-        fs->sample_buffer = av_malloc(9 * (fs->width+6) * sizeof(*fs->sample_buffer));
+        fs->sample_buffer = av_malloc(3*4 * (fs->width+6) * sizeof(*fs->sample_buffer));
         if (!fs->sample_buffer)
             return AVERROR(ENOMEM);
     }
@@ -780,7 +785,7 @@ static int write_extra_header(FFV1Context *f){
     put_rac(c, state, 1); //chroma planes
         put_symbol(c, state, f->chroma_h_shift, 0);
         put_symbol(c, state, f->chroma_v_shift, 0);
-    put_rac(c, state, 0); //no transparency plane
+    put_rac(c, state, f->transparency);
     put_symbol(c, state, f->num_h_slices-1, 0);
     put_symbol(c, state, f->num_v_slices-1, 0);
 
@@ -867,7 +872,7 @@ static av_cold int encode_init(AVCodecContext *avctx)
         for(i=1; i<256; i++)
             s->state_transition[i]=ver2_state[i];
 
-    s->plane_count=2;
+    s->plane_count=3;
     for(i=0; i<256; i++){
         s->quant_table_count=2;
         if(avctx->bits_per_raw_sample <=8){
@@ -932,11 +937,14 @@ static av_cold int encode_init(AVCodecContext *avctx)
         break;
     case PIX_FMT_RGB32:
         s->colorspace= 1;
+        s->transparency= 1;
         break;
     default:
         av_log(avctx, AV_LOG_ERROR, "format not supported\n");
         return -1;
     }
+    if(!s->transparency)
+        s->plane_count= 2;
     avcodec_get_chroma_sub_sample(avctx->pix_fmt, &s->chroma_h_shift, &s->chroma_v_shift);
 
     s->picture_number=0;