Support decoding raw 2bpp in mov, fixes issue 1528.

Originally committed as revision 21027 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/rawdec.c

@@ -47,6 +47,7 @@ static const PixelFormatTag pixelFormatBpsAVI[] = {
 
 static const PixelFormatTag pixelFormatBpsMOV[] = {
     { PIX_FMT_MONOWHITE, 1 },
+    { PIX_FMT_PAL8,      2 },
     { PIX_FMT_PAL8,      4 },
     { PIX_FMT_PAL8,      8 },
     // FIXME swscale does not support 16 bit in .mov, sample 16bit.mov
@@ -115,15 +116,24 @@ static int raw_decode(AVCodecContext *avctx,
     frame->top_field_first = avctx->coded_frame->top_field_first;
 
     //4bpp raw in avi and mov (yes this is ugly ...)
-    if(avctx->bits_per_coded_sample == 4 && avctx->pix_fmt==PIX_FMT_PAL8 &&
+    if((avctx->bits_per_coded_sample == 4 || avctx->bits_per_coded_sample == 2) &&
+       avctx->pix_fmt==PIX_FMT_PAL8 &&
        (!avctx->codec_tag || avctx->codec_tag == MKTAG('r','a','w',' '))){
         int i;
         uint8_t *dst = context->buffer + 256*4;
         buf_size = context->length - 256*4;
+        if (avctx->bits_per_coded_sample == 4){
         for(i=0; 2*i+1 < buf_size; i++){
             dst[2*i+0]= buf[i]>>4;
             dst[2*i+1]= buf[i]&15;
         }
+        } else
+            for(i=0; 4*i+3 < buf_size; i++){
+                dst[4*i+0]= buf[i]>>6;
+                dst[4*i+1]= buf[i]>>4&3;
+                dst[4*i+2]= buf[i]>>2&3;
+                dst[4*i+3]= buf[i]   &3;
+            }
         buf= dst;
     }