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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  */
init_vaapi_pic(VAPictureH264 * va_pic)39 static 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  */
fill_vaapi_pic(VAPictureH264 * va_pic,const H264Picture * pic,int pic_structure)55 static 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). */
82 typedef 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  */
dpb_add(DPB * dpb,const H264Picture * pic)94 static 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. */
fill_vaapi_ReferenceFrames(VAPictureParameterBufferH264 * pic_param,const H264Context * h)125 static 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  */
fill_vaapi_RefPicList(VAPictureH264 RefPicList[32],const H264Ref * ref_list,unsigned int ref_count)159 static 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  */
fill_vaapi_plain_pred_weight_table(const H264Context * h,int list,unsigned char * luma_weight_flag,short luma_weight[32],short luma_offset[32],unsigned char * chroma_weight_flag,short chroma_weight[32][2],short chroma_offset[32][2])188 static 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. */
vaapi_h264_start_frame(AVCodecContext * avctx,av_unused const uint8_t * buffer,av_unused uint32_t size)226 static 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 
304 fail:
305     ff_vaapi_decode_cancel(avctx, pic);
306     return err;
307 }
308 
309 /** End a hardware decoding based frame. */
vaapi_h264_end_frame(AVCodecContext * avctx)310 static 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 
323 finish:
324     return ret;
325 }
326 
327 /** Decode the given H.264 slice with VA API. */
vaapi_h264_decode_slice(AVCodecContext * avctx,const uint8_t * buffer,uint32_t size)328 static 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 
388 const 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