avcodec/vdpau: Support for VDPAU accelerated HEVC decoding

This change introduces basic support for HEVC decoding through vdpau.
Right now, there are problems with the nvidia driver/library implementation
that mean that frames are incorrectly laid out in memory when they are
returned from the decoder, and it is normally impossible to recover the
complete decoded frame due to loss of data from alignment inconsistencies.

I obviously hope that nvidia will be fixing it in due course - I've verified
the problems exist with their example application.

As such, this support is not useful for any real world application, but I
believe that it is correct (with the caveat that the mangled frames may hide
problems) and will work properly once the nvidia problem is fixed.

Right now it appears that any file encoded by x265 or nvenc is decoded
correctly, but that's because these files don't use a bunch of HEVC
features.

Quick summary:

Features that seem to work:

1) Short Term References
2) Scaling Lists
3) Tiling

Features with known problems:

1) Long Term References

It's hard to tell what's going on here. After I read the nvidia example
app that does not set the IsLongTerm flag on LTRs, and changed my code,
a bunch of frames using LTR started to display correctly, but there
are still samples with glitches that are related to LTRs.

In terms of real world files, both x265 and nvenc only use short term
refs from this list. The divx encoder seems similar.

Signed-off-by: Philip Langdale <philipl@overt.org>

1 files changed, 437 insertions, 0 deletions

diff --git a/libavcodec/vdpau_hevc.c b/libavcodec/vdpau_hevc.c
new file mode 100644
index 0000000000..ccf67648d3
--- /dev/null
+++ b/libavcodec/vdpau_hevc.c
@@ -0,0 +1,437 @@
+/*
+ * MPEG-H Part 2 / HEVC / H.265 HW decode acceleration through VDPAU
+ *
+ * Copyright (c) 2013 Philip Langdale
+ *
+ * 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 <vdpau/vdpau.h>
+
+#include "avcodec.h"
+#include "internal.h"
+#include "hevc.h"
+#include "vdpau.h"
+#include "vdpau_internal.h"
+
+static int vdpau_hevc_start_frame(AVCodecContext *avctx,
+                                  const uint8_t *buffer, uint32_t size)
+{
+    HEVCContext *h = avctx->priv_data;
+    HEVCFrame *pic = h->ref;
+    struct vdpau_picture_context *pic_ctx = pic->hwaccel_picture_private;
+
+    VdpPictureInfoHEVC *info = &pic_ctx->info.hevc;
+
+    const HEVCSPS *sps = h->sps;
+    const HEVCPPS *pps = h->pps;
+    const SliceHeader *sh = &h->sh;
+    const ScalingList *sl = pps->scaling_list_data_present_flag ?
+                            &pps->scaling_list : &sps->scaling_list;
+
+    /* init VdpPictureInfoHEVC */
+
+    /* SPS */
+    info->chroma_format_idc = sps->chroma_format_idc;
+    info->separate_colour_plane_flag = sps->separate_colour_plane_flag;
+    info->pic_width_in_luma_samples = sps->width;
+    info->pic_height_in_luma_samples = sps->height;
+    info->bit_depth_luma_minus8 = sps->bit_depth - 8;
+    info->bit_depth_chroma_minus8 = sps->bit_depth - 8;
+    info->log2_max_pic_order_cnt_lsb_minus4 = sps->log2_max_poc_lsb - 4;
+    /** Provides the value corresponding to the nuh_temporal_id of the frame
+        to be decoded. */
+    info->sps_max_dec_pic_buffering_minus1 = sps->temporal_layer[sps->max_sub_layers - 1].max_dec_pic_buffering - 1;
+    info->log2_min_luma_coding_block_size_minus3 = sps->log2_min_cb_size - 3;
+    info->log2_diff_max_min_luma_coding_block_size = sps->log2_diff_max_min_coding_block_size;
+    info->log2_min_transform_block_size_minus2 = sps->log2_min_tb_size - 2;
+    info->log2_diff_max_min_transform_block_size = sps->log2_max_trafo_size - sps->log2_min_tb_size;
+    info->max_transform_hierarchy_depth_inter = sps->max_transform_hierarchy_depth_inter;
+    info->max_transform_hierarchy_depth_intra = sps->max_transform_hierarchy_depth_intra;
+    info->scaling_list_enabled_flag = sps->scaling_list_enable_flag;
+    /** Scaling lists, in diagonal order, to be used for this frame. */
+    for (size_t i = 0; i < 6; i++) {
+        for (size_t j = 0; j < 16; j++) {
+            /** Scaling List for 4x4 quantization matrix,
+                indexed as ScalingList4x4[matrixId][i]. */
+            uint8_t pos = 4 * ff_hevc_diag_scan4x4_y[j] + ff_hevc_diag_scan4x4_x[j];
+            info->ScalingList4x4[i][j] = sl->sl[0][i][pos];
+        }
+        for (size_t j = 0; j < 64; j++) {
+            uint8_t pos = 8 * ff_hevc_diag_scan8x8_y[j] + ff_hevc_diag_scan8x8_x[j];
+            /** Scaling List for 8x8 quantization matrix,
+                indexed as ScalingList8x8[matrixId][i]. */
+            info->ScalingList8x8[i][j] = sl->sl[1][i][pos];
+            /** Scaling List for 16x16 quantization matrix,
+                indexed as ScalingList16x16[matrixId][i]. */
+            info->ScalingList16x16[i][j] = sl->sl[2][i][pos];
+            if (i < 2) {
+                /** Scaling List for 32x32 quantization matrix,
+                    indexed as ScalingList32x32[matrixId][i]. */
+                info->ScalingList32x32[i][j] = sl->sl[3][i * 3][pos];
+            }
+        }
+        /** Scaling List DC Coefficients for 16x16,
+            indexed as ScalingListDCCoeff16x16[matrixId]. */
+        info->ScalingListDCCoeff16x16[i] = sl->sl_dc[0][i];
+        if (i < 2) {
+            /** Scaling List DC Coefficients for 32x32,
+                indexed as ScalingListDCCoeff32x32[matrixId]. */
+            info->ScalingListDCCoeff32x32[i] = sl->sl_dc[1][i * 3];
+        }
+    }
+    info->amp_enabled_flag = sps->amp_enabled_flag;
+    info->sample_adaptive_offset_enabled_flag = sps->sao_enabled;
+    info->pcm_enabled_flag = sps->pcm_enabled_flag;
+    if (info->pcm_enabled_flag) {
+        /** Only needs to be set if pcm_enabled_flag is set. Ignored otherwise. */
+        info->pcm_sample_bit_depth_luma_minus1 = sps->pcm.bit_depth - 1;
+        /** Only needs to be set if pcm_enabled_flag is set. Ignored otherwise. */
+        info->pcm_sample_bit_depth_chroma_minus1 = sps->pcm.bit_depth_chroma - 1;
+        /** Only needs to be set if pcm_enabled_flag is set. Ignored otherwise. */
+        info->log2_min_pcm_luma_coding_block_size_minus3 = sps->pcm.log2_min_pcm_cb_size - 3;
+        /** Only needs to be set if pcm_enabled_flag is set. Ignored otherwise. */
+        info->log2_diff_max_min_pcm_luma_coding_block_size = sps->pcm.log2_max_pcm_cb_size - sps->pcm.log2_min_pcm_cb_size;
+        /** Only needs to be set if pcm_enabled_flag is set. Ignored otherwise. */
+        info->pcm_loop_filter_disabled_flag = sps->pcm.loop_filter_disable_flag;
+    }
+    /** Per spec, when zero, assume short_term_ref_pic_set_sps_flag
+        is also zero. */
+    info->num_short_term_ref_pic_sets = sps->nb_st_rps;
+    info->long_term_ref_pics_present_flag = sps->long_term_ref_pics_present_flag;
+    /** Only needed if long_term_ref_pics_present_flag is set. Ignored
+        otherwise. */
+    info->num_long_term_ref_pics_sps = sps->num_long_term_ref_pics_sps;
+    info->sps_temporal_mvp_enabled_flag = sps->sps_temporal_mvp_enabled_flag;
+    info->strong_intra_smoothing_enabled_flag = sps->sps_strong_intra_smoothing_enable_flag;
+    /** @} */
+
+    /** \name HEVC Picture Parameter Set
+     *
+     * Copies of the HEVC Picture Parameter Set bitstream fields.
+     * @{ */
+    info->dependent_slice_segments_enabled_flag = pps->dependent_slice_segments_enabled_flag;
+    info->output_flag_present_flag = pps->output_flag_present_flag;
+    info->num_extra_slice_header_bits = pps->num_extra_slice_header_bits;
+    info->sign_data_hiding_enabled_flag = pps->sign_data_hiding_flag;
+    info->cabac_init_present_flag = pps->cabac_init_present_flag;
+    info->num_ref_idx_l0_default_active_minus1 = pps->num_ref_idx_l0_default_active - 1;
+    info->num_ref_idx_l1_default_active_minus1 = pps->num_ref_idx_l1_default_active - 1;
+    info->init_qp_minus26 = pps->pic_init_qp_minus26;
+    info->constrained_intra_pred_flag = pps->constrained_intra_pred_flag;
+    info->transform_skip_enabled_flag = pps->transform_skip_enabled_flag;
+    info->cu_qp_delta_enabled_flag = pps->cu_qp_delta_enabled_flag;
+    /** Only needed if cu_qp_delta_enabled_flag is set. Ignored otherwise. */
+    info->diff_cu_qp_delta_depth = pps->diff_cu_qp_delta_depth;
+    info->pps_cb_qp_offset = pps->cb_qp_offset;
+    info->pps_cr_qp_offset = pps->cr_qp_offset;
+    info->pps_slice_chroma_qp_offsets_present_flag = pps->pic_slice_level_chroma_qp_offsets_present_flag;
+    info->weighted_pred_flag = pps->weighted_pred_flag;
+    info->weighted_bipred_flag = pps->weighted_bipred_flag;
+    info->transquant_bypass_enabled_flag = pps->transquant_bypass_enable_flag;
+    info->tiles_enabled_flag = pps->tiles_enabled_flag;
+    info->entropy_coding_sync_enabled_flag = pps->entropy_coding_sync_enabled_flag;
+    if (info->tiles_enabled_flag) {
+        /** Only valid if tiles_enabled_flag is set. Ignored otherwise. */
+        info->num_tile_columns_minus1 = pps->num_tile_columns - 1;
+        /** Only valid if tiles_enabled_flag is set. Ignored otherwise. */
+        info->num_tile_rows_minus1 = pps->num_tile_rows - 1;
+        /** Only valid if tiles_enabled_flag is set. Ignored otherwise. */
+        info->uniform_spacing_flag = pps->uniform_spacing_flag;
+        /** Only need to set 0..num_tile_columns_minus1. The struct
+            definition reserves up to the maximum of 20. Invalid values are
+            ignored. */
+        for (ssize_t i = 0; i < pps->num_tile_columns; i++) {
+            info->column_width_minus1[i] = pps->column_width[i] - 1;
+        }
+        /** Only need to set 0..num_tile_rows_minus1. The struct
+          definition reserves up to the maximum of 22. Invalid values are
+          ignored.*/
+        for (ssize_t i = 0; i < pps->num_tile_rows; i++) {
+            info->row_height_minus1[i] = pps->row_height[i] - 1;
+        }
+        /** Only needed if tiles_enabled_flag is set. Invalid values are
+          ignored. */
+        info->loop_filter_across_tiles_enabled_flag = pps->loop_filter_across_tiles_enabled_flag;
+    }
+    info->pps_loop_filter_across_slices_enabled_flag = pps->seq_loop_filter_across_slices_enabled_flag;
+    info->deblocking_filter_control_present_flag = pps->deblocking_filter_control_present_flag;
+    /** Only valid if deblocking_filter_control_present_flag is set. Ignored
+        otherwise. */
+    info->deblocking_filter_override_enabled_flag = pps->deblocking_filter_override_enabled_flag;
+    /** Only valid if deblocking_filter_control_present_flag is set. Ignored
+        otherwise. */
+    info->pps_deblocking_filter_disabled_flag = pps->disable_dbf;
+    /** Only valid if deblocking_filter_control_present_flag is set and
+        pps_deblocking_filter_disabled_flag is not set. Ignored otherwise.*/
+    info->pps_beta_offset_div2 = pps->beta_offset / 2;
+    /** Only valid if deblocking_filter_control_present_flag is set and
+        pps_deblocking_filter_disabled_flag is not set. Ignored otherwise. */
+    info->pps_tc_offset_div2 = pps->tc_offset / 2;
+    info->lists_modification_present_flag = pps->lists_modification_present_flag;
+    info->log2_parallel_merge_level_minus2 = pps->log2_parallel_merge_level - 2;
+    info->slice_segment_header_extension_present_flag = pps->slice_header_extension_present_flag;
+
+    /** \name HEVC Slice Segment Header
+     *
+     * Copies of the HEVC Slice Segment Header bitstream fields and calculated
+     * values detailed in the specification.
+     * @{ */
+    /** Set to 1 if nal_unit_type is equal to IDR_W_RADL or IDR_N_LP.
+        Set to zero otherwise. */
+    info->IDRPicFlag = IS_IDR(h);
+    /** Set to 1 if nal_unit_type in the range of BLA_W_LP to
+        RSV_IRAP_VCL23, inclusive. Set to zero otherwise.*/
+    info->RAPPicFlag = IS_IRAP(h);
+    /** See section 7.4.7.1 of the specification. */
+    info->CurrRpsIdx = sps->nb_st_rps;
+    if (sh->short_term_ref_pic_set_sps_flag == 1) {
+        for (size_t i = 0; i < sps->nb_st_rps; i++) {
+            if (sh->short_term_rps == &sps->st_rps[i]) {
+                info->CurrRpsIdx = i;
+                break;
+            }
+        }
+    }
+    /** See section 7.4.7.2 of the specification. */
+    info->NumPocTotalCurr = ff_hevc_frame_nb_refs(h);
+    if (sh->short_term_ref_pic_set_sps_flag == 0 && sh->short_term_rps) {
+        /** Corresponds to specification field, NumDeltaPocs[RefRpsIdx].
+            Only applicable when short_term_ref_pic_set_sps_flag == 0.
+            Implementations will ignore this value in other cases. See 7.4.8. */
+        info->NumDeltaPocsOfRefRpsIdx = sh->short_term_rps->num_delta_pocs;
+    }
+    /** Section 7.6.3.1 of the H.265/HEVC Specification defines the syntax of
+        the slice_segment_header. This header contains information that
+        some VDPAU implementations may choose to skip. The VDPAU API
+        requires client applications to track the number of bits used in the
+        slice header for structures associated with short term and long term
+        reference pictures. First, VDPAU requires the number of bits used by
+        the short_term_ref_pic_set array in the slice_segment_header. */
+    info->NumShortTermPictureSliceHeaderBits = sh->short_term_ref_pic_set_size;
+    /** Second, VDPAU requires the number of bits used for long term reference
+        pictures in the slice_segment_header. This is equal to the number
+        of bits used for the contents of the block beginning with
+        "if(long_term_ref_pics_present_flag)". */
+    info->NumLongTermPictureSliceHeaderBits = sh->long_term_ref_pic_set_size;
+    /** @} */
+
+    /** Slice Decoding Process - Picture Order Count */
+    /** The value of PicOrderCntVal of the picture in the access unit
+        containing the SEI message. The picture being decoded. */
+    info->CurrPicOrderCntVal = h->poc;
+
+    /** Slice Decoding Process - Reference Picture Sets */
+    for (size_t i = 0; i < 16; i++) {
+        info->RefPics[i] = VDP_INVALID_HANDLE;
+        info->PicOrderCntVal[i] = 0;
+        info->IsLongTerm[i] = 0;
+    }
+    for (size_t i = 0, j = 0; i < FF_ARRAY_ELEMS(h->DPB); i++) {
+        const HEVCFrame *frame = &h->DPB[i];
+        if (frame != h->ref && (frame->flags & (HEVC_FRAME_FLAG_LONG_REF |
+                                                HEVC_FRAME_FLAG_SHORT_REF))) {
+            if (j > 16) {
+                av_log(avctx, AV_LOG_WARNING,
+                     "VDPAU only supports up to 16 references in the DPB. "
+                     "This frame may not be decoded correctly.\n");
+                break;
+            }
+            /** Array of video reference surfaces.
+                Set any unused positions to VDP_INVALID_HANDLE. */
+            info->RefPics[j] = ff_vdpau_get_surface_id(frame->frame);
+            /** Array of picture order counts. These correspond to positions
+                in the RefPics array. */
+            info->PicOrderCntVal[j] = frame->poc;
+            /** Array used to specify whether a particular RefPic is
+                a long term reference. A value of "1" indicates a long-term
+                reference. */
+            // XXX: Setting this caused glitches in the nvidia implementation
+            // Always setting it to zero, produces correct results
+            //info->IsLongTerm[j] = frame->flags & HEVC_FRAME_FLAG_LONG_REF;
+            info->IsLongTerm[j] = 0;
+            j++;
+        }
+    }
+    /** Copy of specification field, see Section 8.3.2 of the
+        H.265/HEVC Specification. */
+    info->NumPocStCurrBefore = h->rps[ST_CURR_BEF].nb_refs;
+    if (info->NumPocStCurrBefore > 8) {
+        av_log(avctx, AV_LOG_WARNING,
+             "VDPAU only supports up to 8 references in StCurrBefore. "
+             "This frame may not be decoded correctly.\n");
+        info->NumPocStCurrBefore = 8;
+    }
+    /** Copy of specification field, see Section 8.3.2 of the
+        H.265/HEVC Specification. */
+    info->NumPocStCurrAfter = h->rps[ST_CURR_AFT].nb_refs;
+    if (info->NumPocStCurrAfter > 8) {
+        av_log(avctx, AV_LOG_WARNING,
+             "VDPAU only supports up to 8 references in StCurrAfter. "
+             "This frame may not be decoded correctly.\n");
+        info->NumPocStCurrAfter = 8;
+    }
+    /** Copy of specification field, see Section 8.3.2 of the
+        H.265/HEVC Specification. */
+    info->NumPocLtCurr = h->rps[LT_CURR].nb_refs;
+    if (info->NumPocLtCurr > 8) {
+        av_log(avctx, AV_LOG_WARNING,
+             "VDPAU only supports up to 8 references in LtCurr. "
+             "This frame may not be decoded correctly.\n");
+        info->NumPocLtCurr = 8;
+    }
+    /** Reference Picture Set list, one of the short-term RPS. These
+        correspond to positions in the RefPics array. */
+    for (ssize_t i = 0, j = 0; i < h->rps[ST_CURR_BEF].nb_refs; i++) {
+        HEVCFrame *frame = h->rps[ST_CURR_BEF].ref[i];
+        if (frame) {
+            uint8_t found = 0;
+            uintptr_t id = ff_vdpau_get_surface_id(frame->frame);
+            for (size_t k = 0; k < 16; k++) {
+                if (id == info->RefPics[k]) {
+                    info->RefPicSetStCurrBefore[j] = k;
+                    j++;
+                    found = 1;
+                    break;
+                }
+            }
+            if (!found) {
+                av_log(avctx, AV_LOG_WARNING, "missing surface: %p\n",
+                       (void *)id);
+            }
+        } else {
+            av_log(avctx, AV_LOG_WARNING, "missing STR Before frame: %zd\n", i);
+        }
+    }
+    /** Reference Picture Set list, one of the short-term RPS. These
+        correspond to positions in the RefPics array. */
+    for (ssize_t i = 0, j = 0; i < h->rps[ST_CURR_AFT].nb_refs; i++) {
+        HEVCFrame *frame = h->rps[ST_CURR_AFT].ref[i];
+        if (frame) {
+            uint8_t found = 0;
+            uintptr_t id = ff_vdpau_get_surface_id(frame->frame);
+            for (size_t k = 0; k < 16; k++) {
+                if (id == info->RefPics[k]) {
+                    info->RefPicSetStCurrAfter[j] = k;
+                    j++;
+                    found = 1;
+                    break;
+                }
+            }
+            if (!found) {
+                av_log(avctx, AV_LOG_WARNING, "missing surface: %p\n",
+                       (void *)id);
+            }
+        } else {
+            av_log(avctx, AV_LOG_WARNING, "missing STR After frame: %zd\n", i);
+        }
+    }
+    /** Reference Picture Set list, one of the long-term RPS. These
+        correspond to positions in the RefPics array. */
+    for (ssize_t i = 0, j = 0; i < h->rps[LT_CURR].nb_refs; i++) {
+        HEVCFrame *frame = h->rps[LT_CURR].ref[i];
+        if (frame) {
+            uint8_t found = 0;
+            uintptr_t id = ff_vdpau_get_surface_id(frame->frame);
+            for (size_t k = 0; k < 16; k++) {
+                if (id == info->RefPics[k]) {
+                    info->RefPicSetLtCurr[j] = k;
+                    j++;
+                    found = 1;
+                    break;
+                }
+            }
+            if (!found) {
+                av_log(avctx, AV_LOG_WARNING, "missing surface: %p\n",
+                       (void *)id);
+            }
+        } else {
+            av_log(avctx, AV_LOG_WARNING, "missing LTR frame: %zd\n", i);
+        }
+    }
+
+    return ff_vdpau_common_start_frame(pic_ctx, buffer, size);
+}
+
+static const uint8_t start_code_prefix[3] = { 0x00, 0x00, 0x01 };
+
+static int vdpau_hevc_decode_slice(AVCodecContext *avctx,
+                                   const uint8_t *buffer, uint32_t size)
+{
+    HEVCContext *h = avctx->priv_data;
+    struct vdpau_picture_context *pic_ctx = h->ref->hwaccel_picture_private;
+    int val;
+
+    val = ff_vdpau_add_buffer(pic_ctx, start_code_prefix, 3);
+    if (val)
+        return val;
+
+    val = ff_vdpau_add_buffer(pic_ctx, buffer, size);
+    if (val)
+        return val;
+
+    return 0;
+}
+
+static int vdpau_hevc_end_frame(AVCodecContext *avctx)
+{
+    HEVCContext *h = avctx->priv_data;
+    struct vdpau_picture_context *pic_ctx = h->ref->hwaccel_picture_private;
+    int val;
+
+    val = ff_vdpau_common_end_frame(avctx, h->ref->frame, pic_ctx);
+    if (val < 0)
+        return val;
+
+    return 0;
+}
+
+static int vdpau_hevc_init(AVCodecContext *avctx)
+{
+    VdpDecoderProfile profile;
+    uint32_t level = avctx->level;
+
+    switch (avctx->profile) {
+    case FF_PROFILE_HEVC_MAIN:
+        profile = VDP_DECODER_PROFILE_HEVC_MAIN;
+        break;
+    case FF_PROFILE_HEVC_MAIN_10:
+        profile = VDP_DECODER_PROFILE_HEVC_MAIN_10;
+        break;
+    case FF_PROFILE_HEVC_MAIN_STILL_PICTURE:
+        profile = VDP_DECODER_PROFILE_HEVC_MAIN_STILL;
+        break;
+    default:
+        return AVERROR(ENOTSUP);
+    }
+
+    return ff_vdpau_common_init(avctx, profile, level);
+}
+
+AVHWAccel ff_hevc_vdpau_hwaccel = {
+    .name           = "hevc_vdpau",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_HEVC,
+    .pix_fmt        = AV_PIX_FMT_VDPAU,
+    .start_frame    = vdpau_hevc_start_frame,
+    .end_frame      = vdpau_hevc_end_frame,
+    .decode_slice   = vdpau_hevc_decode_slice,
+    .frame_priv_data_size = sizeof(struct vdpau_picture_context),
+    .init           = vdpau_hevc_init,
+    .uninit         = ff_vdpau_common_uninit,
+    .priv_data_size = sizeof(VDPAUContext),
+};