vdpau: add mapping for H.264 Constrained Baseline profile and fallback

Old VDPAU drivers do not support this newly defined profile, so falling
back to Main profile is necessary for backward binary compatibility.
Signed-off-by: Anton Khirnov <anton@khirnov.net>

libavcodec/vdpau.c

@@ -125,6 +125,15 @@ int ff_vdpau_common_init(AVCodecContext *avctx, VdpDecoderProfile profile,
 
     status = decoder_query_caps(vdctx->device, profile, &supported, &max_level,
                                 &max_mb, &max_width, &max_height);
+#ifdef VDP_DECODER_PROFILE_H264_CONSTRAINED_BASELINE
+    if (status != VDP_STATUS_OK && profile == VDP_DECODER_PROFILE_H264_CONSTRAINED_BASELINE) {
+        /* Run-time backward compatibility for libvdpau 0.8 and earlier */
+        profile = VDP_DECODER_PROFILE_H264_MAIN;
+        status = decoder_query_caps(vdctx->device, profile, &supported,
+                                    &max_level, &max_mb,
+                                    &max_width, &max_height);
+    }
+#endif
     if (status != VDP_STATUS_OK)
         return vdpau_error(status);
 

libavcodec/vdpau_h264.c

@@ -213,6 +213,10 @@ static int vdpau_h264_init(AVCodecContext *avctx)
         profile = VDP_DECODER_PROFILE_H264_BASELINE;
         break;
     case FF_PROFILE_H264_CONSTRAINED_BASELINE:
+#ifdef VDP_DECODER_PROFILE_H264_CONSTRAINED_BASELINE
+        profile = VDP_DECODER_PROFILE_H264_CONSTRAINED_BASELINE;
+        break;
+#endif
     case FF_PROFILE_H264_MAIN:
         profile = VDP_DECODER_PROFILE_H264_MAIN;
         break;