MPEG-2 DXVA2 implementation

 It allows VLD MPEG-2 decoding using DXVA2 (GPU assisted decoding API under
VISTA and Windows 7).
 It is implemented by using AVHWAccel API.

Originally committed as revision 23644 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 274 insertions, 0 deletions

diff --git a/libavcodec/dxva2_mpeg2.c b/libavcodec/dxva2_mpeg2.c
new file mode 100644
index 0000000000..3b75dae11c
--- /dev/null
+++ b/libavcodec/dxva2_mpeg2.c
@@ -0,0 +1,274 @@
+/*
+ * MPEG-2 HW acceleration.
+ *
+ * copyright (c) 2010 Laurent Aimar
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "dxva2_internal.h"
+
+#define MAX_SLICES (SLICE_MAX_START_CODE - SLICE_MIN_START_CODE + 1)
+struct dxva2_picture_context {
+    DXVA_PictureParameters pp;
+    DXVA_QmatrixData       qm;
+    unsigned               slice_count;
+    DXVA_SliceInfo         slice[MAX_SLICES];
+
+    const uint8_t          *bitstream;
+    unsigned               bitstream_size;
+};
+
+static void fill_picture_parameters(AVCodecContext *avctx,
+                                    struct dxva_context *ctx,
+                                    const struct MpegEncContext *s,
+                                    DXVA_PictureParameters *pp)
+{
+    const Picture *current_picture = s->current_picture_ptr;
+    int is_field = s->picture_structure != PICT_FRAME;
+
+    memset(pp, 0, sizeof(*pp));
+    pp->wDecodedPictureIndex         = ff_dxva2_get_surface_index(ctx, current_picture);
+    pp->wDeblockedPictureIndex       = 0;
+    if (s->pict_type != FF_I_TYPE)
+        pp->wForwardRefPictureIndex  = ff_dxva2_get_surface_index(ctx, &s->last_picture);
+    else
+        pp->wForwardRefPictureIndex  = 0xffff;
+    if (s->pict_type == FF_B_TYPE)
+        pp->wBackwardRefPictureIndex = ff_dxva2_get_surface_index(ctx, &s->next_picture);
+    else
+        pp->wBackwardRefPictureIndex = 0xffff;
+    pp->wPicWidthInMBminus1          = s->mb_width  - 1;
+    pp->wPicHeightInMBminus1         = (s->mb_height >> is_field) - 1;
+    pp->bMacroblockWidthMinus1       = 15;
+    pp->bMacroblockHeightMinus1      = 15;
+    pp->bBlockWidthMinus1            = 7;
+    pp->bBlockHeightMinus1           = 7;
+    pp->bBPPminus1                   = 7;
+    pp->bPicStructure                = s->picture_structure;
+    pp->bSecondField                 = is_field && !s->first_field;
+    pp->bPicIntra                    = s->pict_type == FF_I_TYPE;
+    pp->bPicBackwardPrediction       = s->pict_type == FF_B_TYPE;
+    pp->bBidirectionalAveragingMode  = 0;
+    pp->bMVprecisionAndChromaRelation= 0; /* FIXME */
+    pp->bChromaFormat                = s->chroma_format;
+    pp->bPicScanFixed                = 1;
+    pp->bPicScanMethod               = s->alternate_scan ? 1 : 0;
+    pp->bPicReadbackRequests         = 0;
+    pp->bRcontrol                    = 0;
+    pp->bPicSpatialResid8            = 0;
+    pp->bPicOverflowBlocks           = 0;
+    pp->bPicExtrapolation            = 0;
+    pp->bPicDeblocked                = 0;
+    pp->bPicDeblockConfined          = 0;
+    pp->bPic4MVallowed               = 0;
+    pp->bPicOBMC                     = 0;
+    pp->bPicBinPB                    = 0;
+    pp->bMV_RPS                      = 0;
+    pp->bReservedBits                = 0;
+    pp->wBitstreamFcodes             = (s->mpeg_f_code[0][0] << 12) |
+                                       (s->mpeg_f_code[0][1] <<  8) |
+                                       (s->mpeg_f_code[1][0] <<  4) |
+                                       (s->mpeg_f_code[1][1]      );
+    pp->wBitstreamPCEelements        = (s->intra_dc_precision         << 14) |
+                                       (s->picture_structure          << 12) |
+                                       (s->top_field_first            << 11) |
+                                       (s->frame_pred_frame_dct       << 10) |
+                                       (s->concealment_motion_vectors <<  9) |
+                                       (s->q_scale_type               <<  8) |
+                                       (s->intra_vlc_format           <<  7) |
+                                       (s->alternate_scan             <<  6) |
+                                       (s->repeat_first_field         <<  5) |
+                                       (s->chroma_420_type            <<  4) |
+                                       (s->progressive_frame          <<  3);
+    pp->bBitstreamConcealmentNeed    = 0;
+    pp->bBitstreamConcealmentMethod  = 0;
+}
+
+static void fill_quantization_matrices(AVCodecContext *avctx,
+                                       struct dxva_context *ctx,
+                                       const struct MpegEncContext *s,
+                                       DXVA_QmatrixData *qm)
+{
+    int i;
+    for (i = 0; i < 4; i++)
+        qm->bNewQmatrix[i] = 1;
+    for (i = 0; i < 64; i++) {
+        int n = s->dsp.idct_permutation[ff_zigzag_direct[i]];
+        qm->Qmatrix[0][i] = s->intra_matrix[n];;
+        qm->Qmatrix[1][i] = s->inter_matrix[n];;
+        qm->Qmatrix[2][i] = s->chroma_intra_matrix[n];;
+        qm->Qmatrix[3][i] = s->chroma_inter_matrix[n];;
+    }
+}
+
+static void fill_slice(AVCodecContext *avctx,
+                       const struct MpegEncContext *s,
+                       DXVA_SliceInfo *slice,
+                       unsigned position,
+                       const uint8_t *buffer, unsigned size)
+{
+    int is_field = s->picture_structure != PICT_FRAME;
+    GetBitContext gb;
+
+    memset(slice, 0, sizeof(*slice));
+    slice->wHorizontalPosition = s->mb_x;
+    slice->wVerticalPosition   = s->mb_y >> is_field;
+    slice->dwSliceBitsInBuffer = 8 * size;
+    slice->dwSliceDataLocation = position;
+    slice->bStartCodeBitOffset = 0;
+    slice->bReservedBits       = 0;
+    /* XXX We store the index of the first MB and it will be fixed later */
+    slice->wNumberMBsInSlice   = (s->mb_y >> is_field) * s->mb_width + s->mb_x;
+    slice->wBadSliceChopping   = 0;
+
+    init_get_bits(&gb, &buffer[4], 8 * (size - 4));
+
+    slice->wQuantizerScaleCode = get_bits(&gb, 5);
+    while (get_bits1(&gb))
+        skip_bits(&gb, 8);
+
+    slice->wMBbitOffset        = 4 * 8 + get_bits_count(&gb);
+}
+static int commit_bitstream_and_slice_buffer(AVCodecContext *avctx,
+                                             DXVA2_DecodeBufferDesc *bs,
+                                             DXVA2_DecodeBufferDesc *sc)
+{
+    const struct MpegEncContext *s = avctx->priv_data;
+    struct dxva_context *ctx = avctx->hwaccel_context;
+    struct dxva2_picture_context *ctx_pic =
+        s->current_picture_ptr->hwaccel_picture_private;
+    const int is_field = s->picture_structure != PICT_FRAME;
+    const unsigned mb_count = s->mb_width * (s->mb_height >> is_field);
+    uint8_t  *dxva_data, *current, *end;
+    unsigned dxva_size;
+    unsigned i;
+
+    if (FAILED(IDirectXVideoDecoder_GetBuffer(ctx->decoder,
+                                              DXVA2_BitStreamDateBufferType,
+                                              &dxva_data, &dxva_size)))
+        return -1;
+    current = dxva_data;
+    end = dxva_data + dxva_size;
+
+    for (i = 0; i < ctx_pic->slice_count; i++) {
+        DXVA_SliceInfo *slice = &ctx_pic->slice[i];
+        unsigned position = slice->dwSliceDataLocation;
+        unsigned size     = slice->dwSliceBitsInBuffer / 8;
+        if (size > end - current) {
+            av_log(avctx, AV_LOG_ERROR, "Failed to build bitstream");
+            break;
+        }
+        slice->dwSliceDataLocation = current - dxva_data;
+
+        if (i < ctx_pic->slice_count - 1)
+            slice->wNumberMBsInSlice =
+                slice[1].wNumberMBsInSlice - slice[0].wNumberMBsInSlice;
+        else
+            slice->wNumberMBsInSlice =
+                mb_count - slice[0].wNumberMBsInSlice;
+
+        memcpy(current, &ctx_pic->bitstream[position], size);
+        current += size;
+    }
+    if (FAILED(IDirectXVideoDecoder_ReleaseBuffer(ctx->decoder,
+                                                  DXVA2_BitStreamDateBufferType)))
+        return -1;
+    if (i < ctx_pic->slice_count)
+        return -1;
+
+    memset(bs, 0, sizeof(*bs));
+    bs->CompressedBufferType = DXVA2_BitStreamDateBufferType;
+    bs->DataSize             = current - dxva_data;
+    bs->NumMBsInBuffer       = mb_count;
+
+    return ff_dxva2_commit_buffer(avctx, ctx, sc,
+                                  DXVA2_SliceControlBufferType,
+                                  ctx_pic->slice,
+                                  ctx_pic->slice_count * sizeof(*ctx_pic->slice),
+                                  mb_count);
+}
+
+static int start_frame(AVCodecContext *avctx,
+                       av_unused const uint8_t *buffer,
+                       av_unused uint32_t size)
+{
+    const struct MpegEncContext *s = avctx->priv_data;
+    struct dxva_context *ctx = avctx->hwaccel_context;
+    struct dxva2_picture_context *ctx_pic =
+        s->current_picture_ptr->hwaccel_picture_private;
+
+    if (!ctx->decoder || !ctx->cfg || ctx->surface_count <= 0)
+        return -1;
+    assert(ctx_pic);
+
+    fill_picture_parameters(avctx, ctx, s, &ctx_pic->pp);
+    fill_quantization_matrices(avctx, ctx, s, &ctx_pic->qm);
+
+    ctx_pic->slice_count    = 0;
+    ctx_pic->bitstream_size = 0;
+    ctx_pic->bitstream      = NULL;
+    return 0;
+}
+
+static int decode_slice(AVCodecContext *avctx,
+                        const uint8_t *buffer, uint32_t size)
+{
+    const struct MpegEncContext *s = avctx->priv_data;
+    struct dxva2_picture_context *ctx_pic =
+        s->current_picture_ptr->hwaccel_picture_private;
+    unsigned position;
+
+    if (ctx_pic->slice_count >= MAX_SLICES)
+        return -1;
+
+    if (!ctx_pic->bitstream)
+        ctx_pic->bitstream = buffer;
+    ctx_pic->bitstream_size += size;
+
+    position = buffer - ctx_pic->bitstream;
+    fill_slice(avctx, s, &ctx_pic->slice[ctx_pic->slice_count++], position,
+               buffer, size);
+    return 0;
+}
+
+static int end_frame(AVCodecContext *avctx)
+{
+    struct MpegEncContext *s = avctx->priv_data;
+    struct dxva2_picture_context *ctx_pic =
+        s->current_picture_ptr->hwaccel_picture_private;
+
+    if (ctx_pic->slice_count <= 0 || ctx_pic->bitstream_size <= 0)
+        return -1;
+    return ff_dxva2_common_end_frame(avctx, s,
+                                     &ctx_pic->pp, sizeof(ctx_pic->pp),
+                                     &ctx_pic->qm, sizeof(ctx_pic->qm),
+                                     commit_bitstream_and_slice_buffer);
+}
+
+AVHWAccel mpeg2_dxva2_hwaccel = {
+    .name           = "mpeg2_dxva2",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = CODEC_ID_MPEG2VIDEO,
+    .pix_fmt        = PIX_FMT_DXVA2_VLD,
+    .capabilities   = 0,
+    .start_frame    = start_frame,
+    .decode_slice   = decode_slice,
+    .end_frame      = end_frame,
+    .priv_data_size = sizeof(struct dxva2_picture_context),
+};
+