1/*
2 * H.264 HW decode acceleration through VA API
3 *
4 * Copyright (C) 2008-2009 Splitted-Desktop Systems
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#include "h264dec.h"
24#include "h264_ps.h"
25#include "hwconfig.h"
26#include "vaapi_decode.h"
27
28/**
29 * @file
30 * This file implements the glue code between FFmpeg's and VA API's
31 * structures for H.264 decoding.
32 */
33
34/**
35 * Initialize an empty VA API picture.
36 *
37 * VA API requires a fixed-size reference picture array.
38 */
39static void init_vaapi_pic(VAPictureH264 *va_pic)
40{
41    va_pic->picture_id          = VA_INVALID_ID;
42    va_pic->flags               = VA_PICTURE_H264_INVALID;
43    va_pic->TopFieldOrderCnt    = 0;
44    va_pic->BottomFieldOrderCnt = 0;
45}
46
47/**
48 * Translate an FFmpeg Picture into its VA API form.
49 *
50 * @param[out] va_pic          A pointer to VA API's own picture struct
51 * @param[in]  pic             A pointer to the FFmpeg picture struct to convert
52 * @param[in]  pic_structure   The picture field type (as defined in mpegvideo.h),
53 *                             supersedes pic's field type if nonzero.
54 */
55static void fill_vaapi_pic(VAPictureH264 *va_pic,
56                           const H264Picture *pic,
57                           int            pic_structure)
58{
59    if (pic_structure == 0)
60        pic_structure = pic->reference;
61    pic_structure &= PICT_FRAME; /* PICT_TOP_FIELD|PICT_BOTTOM_FIELD */
62
63    va_pic->picture_id = ff_vaapi_get_surface_id(pic->f);
64    va_pic->frame_idx  = pic->long_ref ? pic->pic_id : pic->frame_num;
65
66    va_pic->flags      = 0;
67    if (pic_structure != PICT_FRAME)
68        va_pic->flags |= (pic_structure & PICT_TOP_FIELD) ? VA_PICTURE_H264_TOP_FIELD : VA_PICTURE_H264_BOTTOM_FIELD;
69    if (pic->reference)
70        va_pic->flags |= pic->long_ref ? VA_PICTURE_H264_LONG_TERM_REFERENCE : VA_PICTURE_H264_SHORT_TERM_REFERENCE;
71
72    va_pic->TopFieldOrderCnt = 0;
73    if (pic->field_poc[0] != INT_MAX)
74        va_pic->TopFieldOrderCnt = pic->field_poc[0];
75
76    va_pic->BottomFieldOrderCnt = 0;
77    if (pic->field_poc[1] != INT_MAX)
78        va_pic->BottomFieldOrderCnt = pic->field_poc[1];
79}
80
81/** Decoded Picture Buffer (DPB). */
82typedef struct DPB {
83    int            size;        ///< Current number of reference frames in the DPB
84    int            max_size;    ///< Max number of reference frames. This is FF_ARRAY_ELEMS(VAPictureParameterBufferH264.ReferenceFrames)
85    VAPictureH264 *va_pics;     ///< Pointer to VAPictureParameterBufferH264.ReferenceFrames array
86} DPB;
87
88/**
89 * Append picture to the decoded picture buffer, in a VA API form that
90 * merges the second field picture attributes with the first, if
91 * available.  The decoded picture buffer's size must be large enough
92 * to receive the new VA API picture object.
93 */
94static int dpb_add(DPB *dpb, const H264Picture *pic)
95{
96    int i;
97
98    if (dpb->size >= dpb->max_size)
99        return -1;
100
101    for (i = 0; i < dpb->size; i++) {
102        VAPictureH264 * const va_pic = &dpb->va_pics[i];
103        if (va_pic->picture_id == ff_vaapi_get_surface_id(pic->f)) {
104            VAPictureH264 temp_va_pic;
105            fill_vaapi_pic(&temp_va_pic, pic, 0);
106
107            if ((temp_va_pic.flags ^ va_pic->flags) & (VA_PICTURE_H264_TOP_FIELD | VA_PICTURE_H264_BOTTOM_FIELD)) {
108                va_pic->flags |= temp_va_pic.flags & (VA_PICTURE_H264_TOP_FIELD | VA_PICTURE_H264_BOTTOM_FIELD);
109                /* Merge second field */
110                if (temp_va_pic.flags & VA_PICTURE_H264_TOP_FIELD) {
111                    va_pic->TopFieldOrderCnt    = temp_va_pic.TopFieldOrderCnt;
112                } else {
113                    va_pic->BottomFieldOrderCnt = temp_va_pic.BottomFieldOrderCnt;
114                }
115            }
116            return 0;
117        }
118    }
119
120    fill_vaapi_pic(&dpb->va_pics[dpb->size++], pic, 0);
121    return 0;
122}
123
124/** Fill in VA API reference frames array. */
125static int fill_vaapi_ReferenceFrames(VAPictureParameterBufferH264 *pic_param,
126                                      const H264Context            *h)
127{
128    DPB dpb;
129    int i;
130
131    dpb.size     = 0;
132    dpb.max_size = FF_ARRAY_ELEMS(pic_param->ReferenceFrames);
133    dpb.va_pics  = pic_param->ReferenceFrames;
134    for (i = 0; i < dpb.max_size; i++)
135        init_vaapi_pic(&dpb.va_pics[i]);
136
137    for (i = 0; i < h->short_ref_count; i++) {
138        const H264Picture *pic = h->short_ref[i];
139        if (pic && pic->reference && dpb_add(&dpb, pic) < 0)
140            return -1;
141    }
142
143    for (i = 0; i < 16; i++) {
144        const H264Picture *pic = h->long_ref[i];
145        if (pic && pic->reference && dpb_add(&dpb, pic) < 0)
146            return -1;
147    }
148    return 0;
149}
150
151/**
152 * Fill in VA API reference picture lists from the FFmpeg reference
153 * picture list.
154 *
155 * @param[out] RefPicList  VA API internal reference picture list
156 * @param[in]  ref_list    A pointer to the FFmpeg reference list
157 * @param[in]  ref_count   The number of reference pictures in ref_list
158 */
159static void fill_vaapi_RefPicList(VAPictureH264 RefPicList[32],
160                                  const H264Ref *ref_list,
161                                  unsigned int  ref_count)
162{
163    unsigned int i, n = 0;
164    for (i = 0; i < ref_count; i++)
165        if (ref_list[i].reference)
166            fill_vaapi_pic(&RefPicList[n++], ref_list[i].parent,
167                           ref_list[i].reference);
168
169    for (; n < 32; n++)
170        init_vaapi_pic(&RefPicList[n]);
171}
172
173/**
174 * Fill in prediction weight table.
175 *
176 * VA API requires a plain prediction weight table as it does not infer
177 * any value.
178 *
179 * @param[in]  h                   A pointer to the current H.264 context
180 * @param[in]  list                The reference frame list index to use
181 * @param[out] luma_weight_flag    VA API plain luma weight flag
182 * @param[out] luma_weight         VA API plain luma weight table
183 * @param[out] luma_offset         VA API plain luma offset table
184 * @param[out] chroma_weight_flag  VA API plain chroma weight flag
185 * @param[out] chroma_weight       VA API plain chroma weight table
186 * @param[out] chroma_offset       VA API plain chroma offset table
187 */
188static void fill_vaapi_plain_pred_weight_table(const H264Context *h,
189                                               int            list,
190                                               unsigned char *luma_weight_flag,
191                                               short          luma_weight[32],
192                                               short          luma_offset[32],
193                                               unsigned char *chroma_weight_flag,
194                                               short          chroma_weight[32][2],
195                                               short          chroma_offset[32][2])
196{
197    const H264SliceContext *sl = &h->slice_ctx[0];
198    unsigned int i, j;
199
200    *luma_weight_flag    = sl->pwt.luma_weight_flag[list];
201    *chroma_weight_flag  = sl->pwt.chroma_weight_flag[list];
202
203    for (i = 0; i < sl->ref_count[list]; i++) {
204        /* VA API also wants the inferred (default) values, not
205           only what is available in the bitstream (7.4.3.2). */
206        if (sl->pwt.luma_weight_flag[list]) {
207            luma_weight[i] = sl->pwt.luma_weight[i][list][0];
208            luma_offset[i] = sl->pwt.luma_weight[i][list][1];
209        } else {
210            luma_weight[i] = 1 << sl->pwt.luma_log2_weight_denom;
211            luma_offset[i] = 0;
212        }
213        for (j = 0; j < 2; j++) {
214            if (sl->pwt.chroma_weight_flag[list]) {
215                chroma_weight[i][j] = sl->pwt.chroma_weight[i][list][j][0];
216                chroma_offset[i][j] = sl->pwt.chroma_weight[i][list][j][1];
217            } else {
218                chroma_weight[i][j] = 1 << sl->pwt.chroma_log2_weight_denom;
219                chroma_offset[i][j] = 0;
220            }
221        }
222    }
223}
224
225/** Initialize and start decoding a frame with VA API. */
226static int vaapi_h264_start_frame(AVCodecContext          *avctx,
227                                  av_unused const uint8_t *buffer,
228                                  av_unused uint32_t       size)
229{
230    const H264Context *h = avctx->priv_data;
231    VAAPIDecodePicture *pic = h->cur_pic_ptr->hwaccel_picture_private;
232    const PPS *pps = h->ps.pps;
233    const SPS *sps = h->ps.sps;
234    VAPictureParameterBufferH264 pic_param;
235    VAIQMatrixBufferH264 iq_matrix;
236    int err;
237
238    pic->output_surface = ff_vaapi_get_surface_id(h->cur_pic_ptr->f);
239
240    pic_param = (VAPictureParameterBufferH264) {
241        .picture_width_in_mbs_minus1                = h->mb_width - 1,
242        .picture_height_in_mbs_minus1               = h->mb_height - 1,
243        .bit_depth_luma_minus8                      = sps->bit_depth_luma - 8,
244        .bit_depth_chroma_minus8                    = sps->bit_depth_chroma - 8,
245        .num_ref_frames                             = sps->ref_frame_count,
246        .seq_fields.bits = {
247            .chroma_format_idc                      = sps->chroma_format_idc,
248            .residual_colour_transform_flag         = sps->residual_color_transform_flag,
249            .gaps_in_frame_num_value_allowed_flag   = sps->gaps_in_frame_num_allowed_flag,
250            .frame_mbs_only_flag                    = sps->frame_mbs_only_flag,
251            .mb_adaptive_frame_field_flag           = sps->mb_aff,
252            .direct_8x8_inference_flag              = sps->direct_8x8_inference_flag,
253            .MinLumaBiPredSize8x8                   = sps->level_idc >= 31, /* A.3.3.2 */
254            .log2_max_frame_num_minus4              = sps->log2_max_frame_num - 4,
255            .pic_order_cnt_type                     = sps->poc_type,
256            .log2_max_pic_order_cnt_lsb_minus4      = sps->log2_max_poc_lsb - 4,
257            .delta_pic_order_always_zero_flag       = sps->delta_pic_order_always_zero_flag,
258        },
259        .pic_init_qp_minus26                        = pps->init_qp - 26,
260        .pic_init_qs_minus26                        = pps->init_qs - 26,
261        .chroma_qp_index_offset                     = pps->chroma_qp_index_offset[0],
262        .second_chroma_qp_index_offset              = pps->chroma_qp_index_offset[1],
263        .pic_fields.bits = {
264            .entropy_coding_mode_flag               = pps->cabac,
265            .weighted_pred_flag                     = pps->weighted_pred,
266            .weighted_bipred_idc                    = pps->weighted_bipred_idc,
267            .transform_8x8_mode_flag                = pps->transform_8x8_mode,
268            .field_pic_flag                         = h->picture_structure != PICT_FRAME,
269            .constrained_intra_pred_flag            = pps->constrained_intra_pred,
270            .pic_order_present_flag                 = pps->pic_order_present,
271            .deblocking_filter_control_present_flag = pps->deblocking_filter_parameters_present,
272            .redundant_pic_cnt_present_flag         = pps->redundant_pic_cnt_present,
273            .reference_pic_flag                     = h->nal_ref_idc != 0,
274        },
275        .frame_num                                  = h->poc.frame_num,
276    };
277
278    fill_vaapi_pic(&pic_param.CurrPic, h->cur_pic_ptr, h->picture_structure);
279    err = fill_vaapi_ReferenceFrames(&pic_param, h);
280    if (err < 0)
281        goto fail;
282
283    err = ff_vaapi_decode_make_param_buffer(avctx, pic,
284                                            VAPictureParameterBufferType,
285                                            &pic_param, sizeof(pic_param));
286    if (err < 0)
287        goto fail;
288
289    memcpy(iq_matrix.ScalingList4x4,
290           pps->scaling_matrix4, sizeof(iq_matrix.ScalingList4x4));
291    memcpy(iq_matrix.ScalingList8x8[0],
292           pps->scaling_matrix8[0], sizeof(iq_matrix.ScalingList8x8[0]));
293    memcpy(iq_matrix.ScalingList8x8[1],
294           pps->scaling_matrix8[3], sizeof(iq_matrix.ScalingList8x8[0]));
295
296    err = ff_vaapi_decode_make_param_buffer(avctx, pic,
297                                            VAIQMatrixBufferType,
298                                            &iq_matrix, sizeof(iq_matrix));
299    if (err < 0)
300        goto fail;
301
302    return 0;
303
304fail:
305    ff_vaapi_decode_cancel(avctx, pic);
306    return err;
307}
308
309/** End a hardware decoding based frame. */
310static int vaapi_h264_end_frame(AVCodecContext *avctx)
311{
312    const H264Context *h = avctx->priv_data;
313    VAAPIDecodePicture *pic = h->cur_pic_ptr->hwaccel_picture_private;
314    H264SliceContext *sl = &h->slice_ctx[0];
315    int ret;
316
317    ret = ff_vaapi_decode_issue(avctx, pic);
318    if (ret < 0)
319        goto finish;
320
321    ff_h264_draw_horiz_band(h, sl, 0, h->avctx->height);
322
323finish:
324    return ret;
325}
326
327/** Decode the given H.264 slice with VA API. */
328static int vaapi_h264_decode_slice(AVCodecContext *avctx,
329                                   const uint8_t  *buffer,
330                                   uint32_t        size)
331{
332    const H264Context *h = avctx->priv_data;
333    VAAPIDecodePicture *pic = h->cur_pic_ptr->hwaccel_picture_private;
334    const H264SliceContext *sl  = &h->slice_ctx[0];
335    VASliceParameterBufferH264 slice_param;
336    int err;
337
338    slice_param = (VASliceParameterBufferH264) {
339        .slice_data_size               = size,
340        .slice_data_offset             = 0,
341        .slice_data_flag               = VA_SLICE_DATA_FLAG_ALL,
342        .slice_data_bit_offset         = get_bits_count(&sl->gb),
343        .first_mb_in_slice             = (sl->mb_y >> FIELD_OR_MBAFF_PICTURE(h)) * h->mb_width + sl->mb_x,
344        .slice_type                    = ff_h264_get_slice_type(sl),
345        .direct_spatial_mv_pred_flag   = sl->slice_type == AV_PICTURE_TYPE_B ? sl->direct_spatial_mv_pred : 0,
346        .num_ref_idx_l0_active_minus1  = sl->list_count > 0 ? sl->ref_count[0] - 1 : 0,
347        .num_ref_idx_l1_active_minus1  = sl->list_count > 1 ? sl->ref_count[1] - 1 : 0,
348        .cabac_init_idc                = sl->cabac_init_idc,
349        .slice_qp_delta                = sl->qscale - h->ps.pps->init_qp,
350        .disable_deblocking_filter_idc = sl->deblocking_filter < 2 ? !sl->deblocking_filter : sl->deblocking_filter,
351        .slice_alpha_c0_offset_div2    = sl->slice_alpha_c0_offset / 2,
352        .slice_beta_offset_div2        = sl->slice_beta_offset     / 2,
353        .luma_log2_weight_denom        = sl->pwt.luma_log2_weight_denom,
354        .chroma_log2_weight_denom      = sl->pwt.chroma_log2_weight_denom,
355    };
356
357    fill_vaapi_RefPicList(slice_param.RefPicList0, sl->ref_list[0],
358                          sl->list_count > 0 ? sl->ref_count[0] : 0);
359    fill_vaapi_RefPicList(slice_param.RefPicList1, sl->ref_list[1],
360                          sl->list_count > 1 ? sl->ref_count[1] : 0);
361
362    fill_vaapi_plain_pred_weight_table(h, 0,
363                                       &slice_param.luma_weight_l0_flag,
364                                       slice_param.luma_weight_l0,
365                                       slice_param.luma_offset_l0,
366                                       &slice_param.chroma_weight_l0_flag,
367                                       slice_param.chroma_weight_l0,
368                                       slice_param.chroma_offset_l0);
369    fill_vaapi_plain_pred_weight_table(h, 1,
370                                       &slice_param.luma_weight_l1_flag,
371                                       slice_param.luma_weight_l1,
372                                       slice_param.luma_offset_l1,
373                                       &slice_param.chroma_weight_l1_flag,
374                                       slice_param.chroma_weight_l1,
375                                       slice_param.chroma_offset_l1);
376
377    err = ff_vaapi_decode_make_slice_buffer(avctx, pic,
378                                            &slice_param, sizeof(slice_param),
379                                            buffer, size);
380    if (err) {
381        ff_vaapi_decode_cancel(avctx, pic);
382        return err;
383    }
384
385    return 0;
386}
387
388const AVHWAccel ff_h264_vaapi_hwaccel = {
389    .name                 = "h264_vaapi",
390    .type                 = AVMEDIA_TYPE_VIDEO,
391    .id                   = AV_CODEC_ID_H264,
392    .pix_fmt              = AV_PIX_FMT_VAAPI,
393    .start_frame          = &vaapi_h264_start_frame,
394    .end_frame            = &vaapi_h264_end_frame,
395    .decode_slice         = &vaapi_h264_decode_slice,
396    .frame_priv_data_size = sizeof(VAAPIDecodePicture),
397    .init                 = &ff_vaapi_decode_init,
398    .uninit               = &ff_vaapi_decode_uninit,
399    .frame_params         = &ff_vaapi_common_frame_params,
400    .priv_data_size       = sizeof(VAAPIDecodeContext),
401    .caps_internal        = HWACCEL_CAP_ASYNC_SAFE,
402};
403