libutvideo: Don't try and output original_format

The original format field in Ut Video's extradata
should not be used to determine the output format.
Cases can occur where the original format differs
from the actual current format, and thus should
not be used as the output format. Instead, rely
solely on the FOURCC.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/libutvideo.cpp

@@ -51,7 +51,7 @@ static av_cold int utvideo_decode_init(AVCodecContext *avctx)
 {
     UtVideoContext *utv = (UtVideoContext *)avctx->priv_data;
     UtVideoExtra info;
-    int defined_fourcc = 0;
+    int format;
 
     if(avctx->extradata_size != 4*4)
     {
@@ -65,55 +65,28 @@ static av_cold int utvideo_decode_init(AVCodecContext *avctx)
     info.stripes = AV_RL32(avctx->extradata + 8);
     info.flags = AV_RL32(avctx->extradata + 12);
 
-    /* Try to output the original format */
-    switch(UNFCC(info.original_format))
+    /* Pick format based on FOURCC */
+    switch(avctx->codec_tag)
     {
-        case UTVF_YV12:
+        case MKTAG('U', 'L', 'Y', '0'):
             avctx->pix_fmt = PIX_FMT_YUV420P;
+            format = UTVF_YV12;
             break;
-        case UTVF_YUY2:
-        case UTVF_YUYV:
-        case UTVF_YUNV:
+        case MKTAG('U', 'L', 'Y', '2'):
             avctx->pix_fmt = PIX_FMT_YUYV422;
+            format = UTVF_YUY2;
             break;
-        case UTVF_UYVY:
-        case UTVF_UYNV:
-            avctx->pix_fmt = PIX_FMT_UYVY422;
-            break;
-        case UTVF_RGB24_WIN:
+        case MKTAG('U', 'L', 'R', 'G'):
             avctx->pix_fmt = PIX_FMT_BGR24;
+            format = UTVF_RGB24_WIN;
             break;
-        case UTVF_RGB32_WIN:
+        case MKTAG('U', 'L', 'R', 'A'):
             avctx->pix_fmt = PIX_FMT_RGB32;
-            break;
-        case UTVF_ARGB32_WIN:
-            avctx->pix_fmt = PIX_FMT_ARGB;
-            break;
-        case 0:
-            /* Fall back on FOURCC */
-            switch(UNFCC(avctx->codec_tag))
-            {
-                case UTVF_ULY0:
-                    avctx->pix_fmt = PIX_FMT_YUV420P;
-                    defined_fourcc = UTVF_YV12;
-                    break;
-                case UTVF_ULY2:
-                    avctx->pix_fmt = PIX_FMT_YUYV422;
-                    defined_fourcc = UTVF_YUY2;
-                    break;
-                case UTVF_ULRG:
-                    avctx->pix_fmt = PIX_FMT_BGR24;
-                    defined_fourcc = UTVF_RGB24_WIN;
-                    break;
-                case UTVF_ULRA:
-                    avctx->pix_fmt = PIX_FMT_RGB32;
-                    defined_fourcc = UTVF_RGB32_WIN;
-                    break;
-            }
+            format = UTVF_RGB32_WIN;
             break;
         default:
             av_log(avctx, AV_LOG_ERROR,
-                  "Codec ExtraData is Corrupt or Invalid: %X\n", info.original_format);
+                  "Not a Ut Video FOURCC: %X\n", avctx->codec_tag);
             return -1;
     }
 
@@ -146,9 +119,8 @@ static av_cold int utvideo_decode_init(AVCodecContext *avctx)
     utv->codec = CCodec::CreateInstance(UNFCC(avctx->codec_tag), "libavcodec");
 
     /* Initialize Decoding */
-    utv->codec->DecodeBegin(defined_fourcc ? defined_fourcc : UNFCC(info.original_format),
-                            avctx->width, avctx->height, CBGROSSWIDTH_WINDOWS, &info,
-                            sizeof(UtVideoExtra));
+    utv->codec->DecodeBegin(format, avctx->width, avctx->height,
+                            CBGROSSWIDTH_WINDOWS, &info, sizeof(UtVideoExtra));
 
     return 0;
 }