dxva-h264 Fix dxva playback of streams that don't start with an I-Frame.

GPUs with ATI UVDa and UVD+ have trouble when decoding doesn't start on an
I-Frame, and they don't recover on later I-Frames.

The variable to track the first I-Frame is in H264Context so that it can be
reset by code in h264 when initializing the context or flushing.

credits isidrogar, see ticket #11772.
sample on team ftp, samples/11772/CSI_ New York - TV3 - 2008-09-16_1.ts

1 files changed, 74 insertions, 0 deletions

diff --git a/lib/ffmpeg/patches/0055-dxva-h264-Fix-dxva-playback-of-streams-that-don-t-st.patch b/lib/ffmpeg/patches/0055-dxva-h264-Fix-dxva-playback-of-streams-that-don-t-st.patch
new file mode 100644
index 0000000000..ccace31aa5
--- /dev/null
+++ b/lib/ffmpeg/patches/0055-dxva-h264-Fix-dxva-playback-of-streams-that-don-t-st.patch
@@ -0,0 +1,74 @@
+From 6328fc9c25a19f1cba3fae56eeff1eaf69ec6d50 Mon Sep 17 00:00:00 2001
+From: CrystalP <CrystalP@xbmc.org>
+Date: Wed, 5 Oct 2011 13:13:25 -0400
+Subject: [PATCH 5/6] dxva-h264 Fix dxva playback of streams that don't start with an I-Frame.
+
+GPUs with ATI UVDa and UVD+ have trouble when decoding doesn't start on an
+I-Frame, and they don't recover on later I-Frames.
+
+The variable to track the first I-Frame is in H264Context so that it can be
+reset by code in h264 when initializing the context or flushing.
+
+credits isidrogar, see ticket #11772.
+sample on team ftp, samples/11772/CSI_ New York - TV3 - 2008-09-16_1.ts
+---
+ lib/ffmpeg/libavcodec/dxva2_h264.c |    8 ++++++++
+ lib/ffmpeg/libavcodec/h264.c       |    2 ++
+ lib/ffmpeg/libavcodec/h264.h       |    2 ++
+ 3 files changed, 12 insertions(+), 0 deletions(-)
+
+diff --git a/lib/ffmpeg/libavcodec/dxva2_h264.c b/lib/ffmpeg/libavcodec/dxva2_h264.c
+index 4e3370c..2954b89 100644
+--- a/lib/ffmpeg/libavcodec/dxva2_h264.c
++++ b/lib/ffmpeg/libavcodec/dxva2_h264.c
+@@ -430,6 +430,14 @@ static int end_frame(AVCodecContext *avctx)
+ 
+     if (ctx_pic->slice_count <= 0 || ctx_pic->bitstream_size <= 0)
+         return -1;
++
++    // Wait for an I-frame before start decoding. Workaround for ATI UVD and UVD+ GPUs
++    if (!h->got_first_iframe) {
++        if (!(ctx_pic->pp.wBitFields & (1 << 15)))
++            return -1;
++        h->got_first_iframe = 1;
++    }
++
+     return ff_dxva2_common_end_frame(avctx, s,
+                                      &ctx_pic->pp, sizeof(ctx_pic->pp),
+                                      &ctx_pic->qm, sizeof(ctx_pic->qm),
+diff --git a/lib/ffmpeg/libavcodec/h264.c b/lib/ffmpeg/libavcodec/h264.c
+index b84430a..a4d35ae 100644
+--- a/lib/ffmpeg/libavcodec/h264.c
++++ b/lib/ffmpeg/libavcodec/h264.c
+@@ -1479,6 +1479,7 @@ static void flush_dpb(AVCodecContext *avctx){
+             h->delayed_pic[i]->reference= 0;
+         h->delayed_pic[i]= NULL;
+     }
++    h->got_first_iframe = 0;
+     h->outputed_poc= INT_MIN;
+     h->prev_interlaced_frame = 1;
+     idr(h);
+@@ -1848,6 +1849,7 @@ static int decode_slice_header(H264Context *h, H264Context *h0){
+             return -1;
+         s->first_field = 0;
+         h->prev_interlaced_frame = 1;
++        h->got_first_iframe = 0;
+ 
+         init_scan_tables(h);
+         ff_h264_alloc_tables(h);
+diff --git a/lib/ffmpeg/libavcodec/h264.h b/lib/ffmpeg/libavcodec/h264.h
+index b403968..bdca237 100644
+--- a/lib/ffmpeg/libavcodec/h264.h
++++ b/lib/ffmpeg/libavcodec/h264.h
+@@ -587,6 +587,8 @@ typedef struct H264Context{
+     int luma_weight_flag[2];   ///< 7.4.3.2 luma_weight_lX_flag
+     int chroma_weight_flag[2]; ///< 7.4.3.2 chroma_weight_lX_flag
+ 
++    int got_first_iframe;
++
+     // Timestamp stuff
+     int sei_buffering_period_present;  ///< Buffering period SEI flag
+     int initial_cpb_removal_delay[32]; ///< Initial timestamps for CPBs
+-- 
+1.7.3.1.msysgit.0
+