Windows: Add DXVA2 hardware decoding support.

- You will need to download the dxva2api.h from the VLC website, install it in an appropriate include path and re-run configure with --enable-dxva2
- Enable Windows Hardware Acceleration decoder support in the display profile of your choice.
- This is alpha quality at best and this version has only been tested on Vista with an NVidia 9400M chipset (MacBook in bootcamp).
- There is no deinterlacing or other video processing support at this time.
- It is largely stable with MPEG2, H.264 and VC1 support all working though there will be fixes required for certain chipsets and codecs (just as for VDPAU).
- Most stability issues appear to be unrelated to DXVA2 and are general issues with this windows build.

- There is significant picture breakup when starting playback and occasional glitches at other times.

If you are going to test (especially if using the new windows build script), please compile a debug build so we can iron out all of the outstanding issues as quickly as possible.

mythtv/libs/libmythtv/avformatdecoder.cpp

@@ -48,6 +48,10 @@ extern "C" {
 }
 #endif // USING_VDPAU
 
+#ifdef USING_DXVA2
+#include "videoout_d3d.h"
+#endif
+
 extern "C" {
 #include "libavutil/avutil.h"
 #include "libavcodec/ac3_parser.h"
@@ -103,6 +107,7 @@ int  get_avf_buffer_vdpau(struct AVCodecContext *c, AVFrame *pic);
 void release_avf_buffer_vdpau(struct AVCodecContext *c, AVFrame *pic);
 void render_slice_vdpau(struct AVCodecContext *s, const AVFrame *src,
                         int offset[4], int y, int type, int height);
+int  get_avf_buffer_dxva2(struct AVCodecContext *c, AVFrame *pic);
 
 static AVCodec *find_vdpau_decoder(AVCodec *c, enum CodecID id)
 {
@@ -208,6 +213,10 @@ void AvFormatDecoder::GetDecoders(render_opts &opts)
     opts.decoders->append("vdpau");
     (*opts.equiv_decoders)["vdpau"].append("dummy");
 #endif
+#ifdef USING_DXVA2
+    opts.decoders->append("dxva2");
+    (*opts.equiv_decoders)["dxva2"].append("dummy");
+#endif
 
     PrivateDecoder::GetDecoders(opts);
 }
@@ -1249,6 +1258,12 @@ void AvFormatDecoder::InitVideoCodec(AVStream *stream, AVCodecContext *enc,
         enc->draw_horiz_band = render_slice_vdpau;
         enc->slice_flags     = SLICE_FLAG_CODED_ORDER | SLICE_FLAG_ALLOW_FIELD;
     }
+    else if (CODEC_IS_DXVA2(codec, enc))
+    {
+        enc->get_buffer      = get_avf_buffer_dxva2;
+        enc->get_format      = get_format_dxva2;
+        enc->release_buffer  = release_avf_buffer;
+    }
     else if (codec && codec->capabilities & CODEC_CAP_DR1)
     {
         enc->flags          |= CODEC_FLAG_EMU_EDGE;
@@ -1778,6 +1793,25 @@ int AvFormatDecoder::ScanStreams(bool novideo)
                         handled = true;
                     }
 #endif // USING_VDPAU
+#ifdef USING_DXVA2
+                    MythCodecID dxva2_mcid;
+                    PixelFormat pix_fmt = PIX_FMT_YUV420P;
+                    dxva2_mcid = VideoOutputD3D::GetBestSupportedCodec(
+                        width, height, mpeg_version(enc->codec_id),
+                        no_hardware_decoders, pix_fmt);
+
+                    if (dxva2_mcid >= video_codec_id)
+                    {
+                        enc->codec_id = (CodecID)myth2av_codecid(dxva2_mcid);
+                        video_codec_id = dxva2_mcid;
+                        handled = true;
+                        if (!no_hardware_decoders &&
+                            codec_is_dxva2(video_codec_id))
+                        {
+                            enc->pix_fmt = pix_fmt;
+                        }
+                    }
+#endif // USING_DXVA2
                 }
 
                 if (!handled)
@@ -2300,6 +2334,36 @@ void render_slice_vdpau(struct AVCodecContext *s, const AVFrame *src,
     }
 }
 
+int get_avf_buffer_dxva2(struct AVCodecContext *c, AVFrame *pic)
+{
+    AvFormatDecoder *nd = (AvFormatDecoder *)(c->opaque);
+    VideoFrame *frame = nd->GetPlayer()->GetNextVideoFrame();
+    for (int i = 0; i < 4; i++)
+    {
+        pic->data[i]     = NULL;
+        pic->linesize[i] = 0;
+    }
+    pic->reordered_opaque = c->reordered_opaque;
+    pic->opaque      = frame;
+    pic->type        = FF_BUFFER_TYPE_USER;
+    pic->age         = 256 * 256 * 256 *64;
+    frame->pix_fmt   = c->pix_fmt;
+
+#ifdef USING_DXVA2
+    if (nd->GetPlayer()->getVideoOutput())
+    {
+        VideoOutputD3D *vo =
+            dynamic_cast<VideoOutputD3D*>(nd->GetPlayer()->getVideoOutput());
+        if (vo)
+            c->hwaccel_context = (dxva_context*)vo->GetDXVA2Decoder();
+        pic->data[0] = (uint8_t*)frame->buf;
+        pic->data[3] = (uint8_t*)frame->buf;
+    }
+#endif
+
+    return 0;
+}
+
 void AvFormatDecoder::DecodeDTVCC(const uint8_t *buf, uint len)
 {
     if (!len)

mythtv/libs/libmythtv/libmythtv.pro

@@ -581,6 +581,10 @@ mingw {
     SOURCES -= NuppelVideoRecorder.cpp
     SOURCES += videoout_d3d.cpp
 
+    using_dxva2: DEFINES += USING_DXVA2
+    using_dxva2: HEADERS += dxva2decoder.h
+    using_dxva2: SOURCES += dxva2decoder.cpp
+
     LIBS += -lws2_32
 }
 

mythtv/libs/libmythtv/videodisplayprofile.cpp

@@ -639,6 +639,7 @@ QString VideoDisplayProfile::GetDecoderName(const QString &decoder)
         dec_name["ffmpeg"]   = QObject::tr("Standard");
         dec_name["macaccel"] = QObject::tr("Mac hardware acceleration");
         dec_name["vdpau"]    = QObject::tr("NVidia VDPAU acceleration");
+        dec_name["dxva2"]    = QObject::tr("Windows hardware acceleration");
     }
 
     QString ret = decoder;
@@ -673,6 +674,12 @@ QString VideoDisplayProfile::GetDecoderHelp(QString decoder)
             "VDPAU will attempt to use the graphics hardware to "
             "accelerate video decoding and playback.");
 
+    if (decoder == "dxva2")
+        msg += QObject::tr(
+            "DXVA2 will use the graphics hardware to "
+            "accelerate video decoding and playback "
+            "(requires Windows Vista or later).");
+
     return msg;
 }