1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (C) 2019 Pengutronix, Michael Tretter <kernel@pengutronix.de> |
4 | * |
5 | * Convert NAL units between raw byte sequence payloads (RBSP) and C structs |
6 | * |
7 | * The conversion is defined in "ITU-T Rec. H.264 (04/2017) Advanced video |
8 | * coding for generic audiovisual services". Decoder drivers may use the |
9 | * parser to parse RBSP from encoded streams and configure the hardware, if |
10 | * the hardware is not able to parse RBSP itself. Encoder drivers may use the |
11 | * generator to generate the RBSP for SPS/PPS nal units and add them to the |
12 | * encoded stream if the hardware does not generate the units. |
13 | */ |
14 | |
15 | #include <linux/kernel.h> |
16 | #include <linux/types.h> |
17 | #include <linux/string.h> |
18 | #include <linux/v4l2-controls.h> |
19 | |
20 | #include <linux/device.h> |
21 | #include <linux/export.h> |
22 | #include <linux/log2.h> |
23 | |
24 | #include "nal-h264.h" |
25 | #include "nal-rbsp.h" |
26 | |
27 | /* |
28 | * See Rec. ITU-T H.264 (04/2017) Table 7-1 - NAL unit type codes, syntax |
29 | * element categories, and NAL unit type classes |
30 | */ |
31 | enum nal_unit_type { |
32 | SEQUENCE_PARAMETER_SET = 7, |
33 | PICTURE_PARAMETER_SET = 8, |
34 | FILLER_DATA = 12, |
35 | }; |
36 | |
37 | static void nal_h264_write_start_code_prefix(struct rbsp *rbsp) |
38 | { |
39 | u8 *p = rbsp->data + DIV_ROUND_UP(rbsp->pos, 8); |
40 | int i = 4; |
41 | |
42 | if (DIV_ROUND_UP(rbsp->pos, 8) + i > rbsp->size) { |
43 | rbsp->error = -EINVAL; |
44 | return; |
45 | } |
46 | |
47 | p[0] = 0x00; |
48 | p[1] = 0x00; |
49 | p[2] = 0x00; |
50 | p[3] = 0x01; |
51 | |
52 | rbsp->pos += i * 8; |
53 | } |
54 | |
55 | static void nal_h264_read_start_code_prefix(struct rbsp *rbsp) |
56 | { |
57 | u8 *p = rbsp->data + DIV_ROUND_UP(rbsp->pos, 8); |
58 | int i = 4; |
59 | |
60 | if (DIV_ROUND_UP(rbsp->pos, 8) + i > rbsp->size) { |
61 | rbsp->error = -EINVAL; |
62 | return; |
63 | } |
64 | |
65 | if (p[0] != 0x00 || p[1] != 0x00 || p[2] != 0x00 || p[3] != 0x01) { |
66 | rbsp->error = -EINVAL; |
67 | return; |
68 | } |
69 | |
70 | rbsp->pos += i * 8; |
71 | } |
72 | |
73 | static void nal_h264_write_filler_data(struct rbsp *rbsp) |
74 | { |
75 | u8 *p = rbsp->data + DIV_ROUND_UP(rbsp->pos, 8); |
76 | int i; |
77 | |
78 | /* Keep 1 byte extra for terminating the NAL unit */ |
79 | i = rbsp->size - DIV_ROUND_UP(rbsp->pos, 8) - 1; |
80 | memset(p, 0xff, i); |
81 | rbsp->pos += i * 8; |
82 | } |
83 | |
84 | static void nal_h264_read_filler_data(struct rbsp *rbsp) |
85 | { |
86 | u8 *p = rbsp->data + DIV_ROUND_UP(rbsp->pos, 8); |
87 | |
88 | while (*p == 0xff) { |
89 | if (DIV_ROUND_UP(rbsp->pos, 8) > rbsp->size) { |
90 | rbsp->error = -EINVAL; |
91 | return; |
92 | } |
93 | |
94 | p++; |
95 | rbsp->pos += 8; |
96 | } |
97 | } |
98 | |
99 | static void nal_h264_rbsp_hrd_parameters(struct rbsp *rbsp, |
100 | struct nal_h264_hrd_parameters *hrd) |
101 | { |
102 | unsigned int i; |
103 | |
104 | if (!hrd) { |
105 | rbsp->error = -EINVAL; |
106 | return; |
107 | } |
108 | |
109 | rbsp_uev(rbsp, value: &hrd->cpb_cnt_minus1); |
110 | rbsp_bits(rbsp, n: 4, value: &hrd->bit_rate_scale); |
111 | rbsp_bits(rbsp, n: 4, value: &hrd->cpb_size_scale); |
112 | |
113 | for (i = 0; i <= hrd->cpb_cnt_minus1; i++) { |
114 | rbsp_uev(rbsp, value: &hrd->bit_rate_value_minus1[i]); |
115 | rbsp_uev(rbsp, value: &hrd->cpb_size_value_minus1[i]); |
116 | rbsp_bit(rbsp, value: &hrd->cbr_flag[i]); |
117 | } |
118 | |
119 | rbsp_bits(rbsp, n: 5, value: &hrd->initial_cpb_removal_delay_length_minus1); |
120 | rbsp_bits(rbsp, n: 5, value: &hrd->cpb_removal_delay_length_minus1); |
121 | rbsp_bits(rbsp, n: 5, value: &hrd->dpb_output_delay_length_minus1); |
122 | rbsp_bits(rbsp, n: 5, value: &hrd->time_offset_length); |
123 | } |
124 | |
125 | static void nal_h264_rbsp_vui_parameters(struct rbsp *rbsp, |
126 | struct nal_h264_vui_parameters *vui) |
127 | { |
128 | if (!vui) { |
129 | rbsp->error = -EINVAL; |
130 | return; |
131 | } |
132 | |
133 | rbsp_bit(rbsp, value: &vui->aspect_ratio_info_present_flag); |
134 | if (vui->aspect_ratio_info_present_flag) { |
135 | rbsp_bits(rbsp, n: 8, value: &vui->aspect_ratio_idc); |
136 | if (vui->aspect_ratio_idc == 255) { |
137 | rbsp_bits(rbsp, n: 16, value: &vui->sar_width); |
138 | rbsp_bits(rbsp, n: 16, value: &vui->sar_height); |
139 | } |
140 | } |
141 | |
142 | rbsp_bit(rbsp, value: &vui->overscan_info_present_flag); |
143 | if (vui->overscan_info_present_flag) |
144 | rbsp_bit(rbsp, value: &vui->overscan_appropriate_flag); |
145 | |
146 | rbsp_bit(rbsp, value: &vui->video_signal_type_present_flag); |
147 | if (vui->video_signal_type_present_flag) { |
148 | rbsp_bits(rbsp, n: 3, value: &vui->video_format); |
149 | rbsp_bit(rbsp, value: &vui->video_full_range_flag); |
150 | |
151 | rbsp_bit(rbsp, value: &vui->colour_description_present_flag); |
152 | if (vui->colour_description_present_flag) { |
153 | rbsp_bits(rbsp, n: 8, value: &vui->colour_primaries); |
154 | rbsp_bits(rbsp, n: 8, value: &vui->transfer_characteristics); |
155 | rbsp_bits(rbsp, n: 8, value: &vui->matrix_coefficients); |
156 | } |
157 | } |
158 | |
159 | rbsp_bit(rbsp, value: &vui->chroma_loc_info_present_flag); |
160 | if (vui->chroma_loc_info_present_flag) { |
161 | rbsp_uev(rbsp, value: &vui->chroma_sample_loc_type_top_field); |
162 | rbsp_uev(rbsp, value: &vui->chroma_sample_loc_type_bottom_field); |
163 | } |
164 | |
165 | rbsp_bit(rbsp, value: &vui->timing_info_present_flag); |
166 | if (vui->timing_info_present_flag) { |
167 | rbsp_bits(rbsp, n: 32, value: &vui->num_units_in_tick); |
168 | rbsp_bits(rbsp, n: 32, value: &vui->time_scale); |
169 | rbsp_bit(rbsp, value: &vui->fixed_frame_rate_flag); |
170 | } |
171 | |
172 | rbsp_bit(rbsp, value: &vui->nal_hrd_parameters_present_flag); |
173 | if (vui->nal_hrd_parameters_present_flag) |
174 | nal_h264_rbsp_hrd_parameters(rbsp, hrd: &vui->nal_hrd_parameters); |
175 | |
176 | rbsp_bit(rbsp, value: &vui->vcl_hrd_parameters_present_flag); |
177 | if (vui->vcl_hrd_parameters_present_flag) |
178 | nal_h264_rbsp_hrd_parameters(rbsp, hrd: &vui->vcl_hrd_parameters); |
179 | |
180 | if (vui->nal_hrd_parameters_present_flag || |
181 | vui->vcl_hrd_parameters_present_flag) |
182 | rbsp_bit(rbsp, value: &vui->low_delay_hrd_flag); |
183 | |
184 | rbsp_bit(rbsp, value: &vui->pic_struct_present_flag); |
185 | |
186 | rbsp_bit(rbsp, value: &vui->bitstream_restriction_flag); |
187 | if (vui->bitstream_restriction_flag) { |
188 | rbsp_bit(rbsp, value: &vui->motion_vectors_over_pic_boundaries_flag); |
189 | rbsp_uev(rbsp, value: &vui->max_bytes_per_pic_denom); |
190 | rbsp_uev(rbsp, value: &vui->max_bits_per_mb_denom); |
191 | rbsp_uev(rbsp, value: &vui->log2_max_mv_length_horizontal); |
192 | rbsp_uev(rbsp, value: &vui->log21_max_mv_length_vertical); |
193 | rbsp_uev(rbsp, value: &vui->max_num_reorder_frames); |
194 | rbsp_uev(rbsp, value: &vui->max_dec_frame_buffering); |
195 | } |
196 | } |
197 | |
198 | static void nal_h264_rbsp_sps(struct rbsp *rbsp, struct nal_h264_sps *sps) |
199 | { |
200 | unsigned int i; |
201 | |
202 | if (!sps) { |
203 | rbsp->error = -EINVAL; |
204 | return; |
205 | } |
206 | |
207 | rbsp_bits(rbsp, n: 8, value: &sps->profile_idc); |
208 | rbsp_bit(rbsp, value: &sps->constraint_set0_flag); |
209 | rbsp_bit(rbsp, value: &sps->constraint_set1_flag); |
210 | rbsp_bit(rbsp, value: &sps->constraint_set2_flag); |
211 | rbsp_bit(rbsp, value: &sps->constraint_set3_flag); |
212 | rbsp_bit(rbsp, value: &sps->constraint_set4_flag); |
213 | rbsp_bit(rbsp, value: &sps->constraint_set5_flag); |
214 | rbsp_bits(rbsp, n: 2, value: &sps->reserved_zero_2bits); |
215 | rbsp_bits(rbsp, n: 8, value: &sps->level_idc); |
216 | |
217 | rbsp_uev(rbsp, value: &sps->seq_parameter_set_id); |
218 | |
219 | if (sps->profile_idc == 100 || sps->profile_idc == 110 || |
220 | sps->profile_idc == 122 || sps->profile_idc == 244 || |
221 | sps->profile_idc == 44 || sps->profile_idc == 83 || |
222 | sps->profile_idc == 86 || sps->profile_idc == 118 || |
223 | sps->profile_idc == 128 || sps->profile_idc == 138 || |
224 | sps->profile_idc == 139 || sps->profile_idc == 134 || |
225 | sps->profile_idc == 135) { |
226 | rbsp_uev(rbsp, value: &sps->chroma_format_idc); |
227 | |
228 | if (sps->chroma_format_idc == 3) |
229 | rbsp_bit(rbsp, value: &sps->separate_colour_plane_flag); |
230 | rbsp_uev(rbsp, value: &sps->bit_depth_luma_minus8); |
231 | rbsp_uev(rbsp, value: &sps->bit_depth_chroma_minus8); |
232 | rbsp_bit(rbsp, value: &sps->qpprime_y_zero_transform_bypass_flag); |
233 | rbsp_bit(rbsp, value: &sps->seq_scaling_matrix_present_flag); |
234 | if (sps->seq_scaling_matrix_present_flag) |
235 | rbsp->error = -EINVAL; |
236 | } |
237 | |
238 | rbsp_uev(rbsp, value: &sps->log2_max_frame_num_minus4); |
239 | |
240 | rbsp_uev(rbsp, value: &sps->pic_order_cnt_type); |
241 | switch (sps->pic_order_cnt_type) { |
242 | case 0: |
243 | rbsp_uev(rbsp, value: &sps->log2_max_pic_order_cnt_lsb_minus4); |
244 | break; |
245 | case 1: |
246 | rbsp_bit(rbsp, value: &sps->delta_pic_order_always_zero_flag); |
247 | rbsp_sev(rbsp, value: &sps->offset_for_non_ref_pic); |
248 | rbsp_sev(rbsp, value: &sps->offset_for_top_to_bottom_field); |
249 | |
250 | rbsp_uev(rbsp, value: &sps->num_ref_frames_in_pic_order_cnt_cycle); |
251 | for (i = 0; i < sps->num_ref_frames_in_pic_order_cnt_cycle; i++) |
252 | rbsp_sev(rbsp, value: &sps->offset_for_ref_frame[i]); |
253 | break; |
254 | default: |
255 | rbsp->error = -EINVAL; |
256 | break; |
257 | } |
258 | |
259 | rbsp_uev(rbsp, value: &sps->max_num_ref_frames); |
260 | rbsp_bit(rbsp, value: &sps->gaps_in_frame_num_value_allowed_flag); |
261 | rbsp_uev(rbsp, value: &sps->pic_width_in_mbs_minus1); |
262 | rbsp_uev(rbsp, value: &sps->pic_height_in_map_units_minus1); |
263 | |
264 | rbsp_bit(rbsp, value: &sps->frame_mbs_only_flag); |
265 | if (!sps->frame_mbs_only_flag) |
266 | rbsp_bit(rbsp, value: &sps->mb_adaptive_frame_field_flag); |
267 | |
268 | rbsp_bit(rbsp, value: &sps->direct_8x8_inference_flag); |
269 | |
270 | rbsp_bit(rbsp, value: &sps->frame_cropping_flag); |
271 | if (sps->frame_cropping_flag) { |
272 | rbsp_uev(rbsp, value: &sps->crop_left); |
273 | rbsp_uev(rbsp, value: &sps->crop_right); |
274 | rbsp_uev(rbsp, value: &sps->crop_top); |
275 | rbsp_uev(rbsp, value: &sps->crop_bottom); |
276 | } |
277 | |
278 | rbsp_bit(rbsp, value: &sps->vui_parameters_present_flag); |
279 | if (sps->vui_parameters_present_flag) |
280 | nal_h264_rbsp_vui_parameters(rbsp, vui: &sps->vui); |
281 | } |
282 | |
283 | static void nal_h264_rbsp_pps(struct rbsp *rbsp, struct nal_h264_pps *pps) |
284 | { |
285 | int i; |
286 | |
287 | rbsp_uev(rbsp, value: &pps->pic_parameter_set_id); |
288 | rbsp_uev(rbsp, value: &pps->seq_parameter_set_id); |
289 | rbsp_bit(rbsp, value: &pps->entropy_coding_mode_flag); |
290 | rbsp_bit(rbsp, value: &pps->bottom_field_pic_order_in_frame_present_flag); |
291 | rbsp_uev(rbsp, value: &pps->num_slice_groups_minus1); |
292 | if (pps->num_slice_groups_minus1 > 0) { |
293 | rbsp_uev(rbsp, value: &pps->slice_group_map_type); |
294 | switch (pps->slice_group_map_type) { |
295 | case 0: |
296 | for (i = 0; i < pps->num_slice_groups_minus1; i++) |
297 | rbsp_uev(rbsp, value: &pps->run_length_minus1[i]); |
298 | break; |
299 | case 2: |
300 | for (i = 0; i < pps->num_slice_groups_minus1; i++) { |
301 | rbsp_uev(rbsp, value: &pps->top_left[i]); |
302 | rbsp_uev(rbsp, value: &pps->bottom_right[i]); |
303 | } |
304 | break; |
305 | case 3: case 4: case 5: |
306 | rbsp_bit(rbsp, value: &pps->slice_group_change_direction_flag); |
307 | rbsp_uev(rbsp, value: &pps->slice_group_change_rate_minus1); |
308 | break; |
309 | case 6: |
310 | rbsp_uev(rbsp, value: &pps->pic_size_in_map_units_minus1); |
311 | for (i = 0; i < pps->pic_size_in_map_units_minus1; i++) |
312 | rbsp_bits(rbsp, |
313 | order_base_2(pps->num_slice_groups_minus1 + 1), |
314 | value: &pps->slice_group_id[i]); |
315 | break; |
316 | default: |
317 | break; |
318 | } |
319 | } |
320 | rbsp_uev(rbsp, value: &pps->num_ref_idx_l0_default_active_minus1); |
321 | rbsp_uev(rbsp, value: &pps->num_ref_idx_l1_default_active_minus1); |
322 | rbsp_bit(rbsp, value: &pps->weighted_pred_flag); |
323 | rbsp_bits(rbsp, n: 2, value: &pps->weighted_bipred_idc); |
324 | rbsp_sev(rbsp, value: &pps->pic_init_qp_minus26); |
325 | rbsp_sev(rbsp, value: &pps->pic_init_qs_minus26); |
326 | rbsp_sev(rbsp, value: &pps->chroma_qp_index_offset); |
327 | rbsp_bit(rbsp, value: &pps->deblocking_filter_control_present_flag); |
328 | rbsp_bit(rbsp, value: &pps->constrained_intra_pred_flag); |
329 | rbsp_bit(rbsp, value: &pps->redundant_pic_cnt_present_flag); |
330 | if (/* more_rbsp_data() */ false) { |
331 | rbsp_bit(rbsp, value: &pps->transform_8x8_mode_flag); |
332 | rbsp_bit(rbsp, value: &pps->pic_scaling_matrix_present_flag); |
333 | if (pps->pic_scaling_matrix_present_flag) |
334 | rbsp->error = -EINVAL; |
335 | rbsp_sev(rbsp, value: &pps->second_chroma_qp_index_offset); |
336 | } |
337 | } |
338 | |
339 | /** |
340 | * nal_h264_write_sps() - Write SPS NAL unit into RBSP format |
341 | * @dev: device pointer |
342 | * @dest: the buffer that is filled with RBSP data |
343 | * @n: maximum size of @dest in bytes |
344 | * @sps: &struct nal_h264_sps to convert to RBSP |
345 | * |
346 | * Convert @sps to RBSP data and write it into @dest. |
347 | * |
348 | * The size of the SPS NAL unit is not known in advance and this function will |
349 | * fail, if @dest does not hold sufficient space for the SPS NAL unit. |
350 | * |
351 | * Return: number of bytes written to @dest or negative error code |
352 | */ |
353 | ssize_t nal_h264_write_sps(const struct device *dev, |
354 | void *dest, size_t n, struct nal_h264_sps *sps) |
355 | { |
356 | struct rbsp rbsp; |
357 | unsigned int forbidden_zero_bit = 0; |
358 | unsigned int nal_ref_idc = 0; |
359 | unsigned int nal_unit_type = SEQUENCE_PARAMETER_SET; |
360 | |
361 | if (!dest) |
362 | return -EINVAL; |
363 | |
364 | rbsp_init(rbsp: &rbsp, addr: dest, size: n, ops: &write); |
365 | |
366 | nal_h264_write_start_code_prefix(rbsp: &rbsp); |
367 | |
368 | rbsp_bit(rbsp: &rbsp, value: &forbidden_zero_bit); |
369 | rbsp_bits(rbsp: &rbsp, n: 2, value: &nal_ref_idc); |
370 | rbsp_bits(rbsp: &rbsp, n: 5, value: &nal_unit_type); |
371 | |
372 | nal_h264_rbsp_sps(rbsp: &rbsp, sps); |
373 | |
374 | rbsp_trailing_bits(rbsp: &rbsp); |
375 | |
376 | if (rbsp.error) |
377 | return rbsp.error; |
378 | |
379 | return DIV_ROUND_UP(rbsp.pos, 8); |
380 | } |
381 | EXPORT_SYMBOL_GPL(nal_h264_write_sps); |
382 | |
383 | /** |
384 | * nal_h264_read_sps() - Read SPS NAL unit from RBSP format |
385 | * @dev: device pointer |
386 | * @sps: the &struct nal_h264_sps to fill from the RBSP data |
387 | * @src: the buffer that contains the RBSP data |
388 | * @n: size of @src in bytes |
389 | * |
390 | * Read RBSP data from @src and use it to fill @sps. |
391 | * |
392 | * Return: number of bytes read from @src or negative error code |
393 | */ |
394 | ssize_t nal_h264_read_sps(const struct device *dev, |
395 | struct nal_h264_sps *sps, void *src, size_t n) |
396 | { |
397 | struct rbsp rbsp; |
398 | unsigned int forbidden_zero_bit; |
399 | unsigned int nal_ref_idc; |
400 | unsigned int nal_unit_type; |
401 | |
402 | if (!src) |
403 | return -EINVAL; |
404 | |
405 | rbsp_init(rbsp: &rbsp, addr: src, size: n, ops: &read); |
406 | |
407 | nal_h264_read_start_code_prefix(rbsp: &rbsp); |
408 | |
409 | rbsp_bit(rbsp: &rbsp, value: &forbidden_zero_bit); |
410 | rbsp_bits(rbsp: &rbsp, n: 2, value: &nal_ref_idc); |
411 | rbsp_bits(rbsp: &rbsp, n: 5, value: &nal_unit_type); |
412 | |
413 | if (rbsp.error || |
414 | forbidden_zero_bit != 0 || |
415 | nal_ref_idc != 0 || |
416 | nal_unit_type != SEQUENCE_PARAMETER_SET) |
417 | return -EINVAL; |
418 | |
419 | nal_h264_rbsp_sps(rbsp: &rbsp, sps); |
420 | |
421 | rbsp_trailing_bits(rbsp: &rbsp); |
422 | |
423 | if (rbsp.error) |
424 | return rbsp.error; |
425 | |
426 | return DIV_ROUND_UP(rbsp.pos, 8); |
427 | } |
428 | EXPORT_SYMBOL_GPL(nal_h264_read_sps); |
429 | |
430 | /** |
431 | * nal_h264_write_pps() - Write PPS NAL unit into RBSP format |
432 | * @dev: device pointer |
433 | * @dest: the buffer that is filled with RBSP data |
434 | * @n: maximum size of @dest in bytes |
435 | * @pps: &struct nal_h264_pps to convert to RBSP |
436 | * |
437 | * Convert @pps to RBSP data and write it into @dest. |
438 | * |
439 | * The size of the PPS NAL unit is not known in advance and this function will |
440 | * fail, if @dest does not hold sufficient space for the PPS NAL unit. |
441 | * |
442 | * Return: number of bytes written to @dest or negative error code |
443 | */ |
444 | ssize_t nal_h264_write_pps(const struct device *dev, |
445 | void *dest, size_t n, struct nal_h264_pps *pps) |
446 | { |
447 | struct rbsp rbsp; |
448 | unsigned int forbidden_zero_bit = 0; |
449 | unsigned int nal_ref_idc = 0; |
450 | unsigned int nal_unit_type = PICTURE_PARAMETER_SET; |
451 | |
452 | if (!dest) |
453 | return -EINVAL; |
454 | |
455 | rbsp_init(rbsp: &rbsp, addr: dest, size: n, ops: &write); |
456 | |
457 | nal_h264_write_start_code_prefix(rbsp: &rbsp); |
458 | |
459 | /* NAL unit header */ |
460 | rbsp_bit(rbsp: &rbsp, value: &forbidden_zero_bit); |
461 | rbsp_bits(rbsp: &rbsp, n: 2, value: &nal_ref_idc); |
462 | rbsp_bits(rbsp: &rbsp, n: 5, value: &nal_unit_type); |
463 | |
464 | nal_h264_rbsp_pps(rbsp: &rbsp, pps); |
465 | |
466 | rbsp_trailing_bits(rbsp: &rbsp); |
467 | |
468 | if (rbsp.error) |
469 | return rbsp.error; |
470 | |
471 | return DIV_ROUND_UP(rbsp.pos, 8); |
472 | } |
473 | EXPORT_SYMBOL_GPL(nal_h264_write_pps); |
474 | |
475 | /** |
476 | * nal_h264_read_pps() - Read PPS NAL unit from RBSP format |
477 | * @dev: device pointer |
478 | * @pps: the &struct nal_h264_pps to fill from the RBSP data |
479 | * @src: the buffer that contains the RBSP data |
480 | * @n: size of @src in bytes |
481 | * |
482 | * Read RBSP data from @src and use it to fill @pps. |
483 | * |
484 | * Return: number of bytes read from @src or negative error code |
485 | */ |
486 | ssize_t nal_h264_read_pps(const struct device *dev, |
487 | struct nal_h264_pps *pps, void *src, size_t n) |
488 | { |
489 | struct rbsp rbsp; |
490 | |
491 | if (!src) |
492 | return -EINVAL; |
493 | |
494 | rbsp_init(rbsp: &rbsp, addr: src, size: n, ops: &read); |
495 | |
496 | nal_h264_read_start_code_prefix(rbsp: &rbsp); |
497 | |
498 | /* NAL unit header */ |
499 | rbsp.pos += 8; |
500 | |
501 | nal_h264_rbsp_pps(rbsp: &rbsp, pps); |
502 | |
503 | rbsp_trailing_bits(rbsp: &rbsp); |
504 | |
505 | if (rbsp.error) |
506 | return rbsp.error; |
507 | |
508 | return DIV_ROUND_UP(rbsp.pos, 8); |
509 | } |
510 | EXPORT_SYMBOL_GPL(nal_h264_read_pps); |
511 | |
512 | /** |
513 | * nal_h264_write_filler() - Write filler data RBSP |
514 | * @dev: device pointer |
515 | * @dest: buffer to fill with filler data |
516 | * @n: size of the buffer to fill with filler data |
517 | * |
518 | * Write a filler data RBSP to @dest with a size of @n bytes and return the |
519 | * number of written filler data bytes. |
520 | * |
521 | * Use this function to generate dummy data in an RBSP data stream that can be |
522 | * safely ignored by h264 decoders. |
523 | * |
524 | * The RBSP format of the filler data is specified in Rec. ITU-T H.264 |
525 | * (04/2017) 7.3.2.7 Filler data RBSP syntax. |
526 | * |
527 | * Return: number of filler data bytes (including marker) or negative error |
528 | */ |
529 | ssize_t nal_h264_write_filler(const struct device *dev, void *dest, size_t n) |
530 | { |
531 | struct rbsp rbsp; |
532 | unsigned int forbidden_zero_bit = 0; |
533 | unsigned int nal_ref_idc = 0; |
534 | unsigned int nal_unit_type = FILLER_DATA; |
535 | |
536 | if (!dest) |
537 | return -EINVAL; |
538 | |
539 | rbsp_init(rbsp: &rbsp, addr: dest, size: n, ops: &write); |
540 | |
541 | nal_h264_write_start_code_prefix(rbsp: &rbsp); |
542 | |
543 | rbsp_bit(rbsp: &rbsp, value: &forbidden_zero_bit); |
544 | rbsp_bits(rbsp: &rbsp, n: 2, value: &nal_ref_idc); |
545 | rbsp_bits(rbsp: &rbsp, n: 5, value: &nal_unit_type); |
546 | |
547 | nal_h264_write_filler_data(rbsp: &rbsp); |
548 | |
549 | rbsp_trailing_bits(rbsp: &rbsp); |
550 | |
551 | return DIV_ROUND_UP(rbsp.pos, 8); |
552 | } |
553 | EXPORT_SYMBOL_GPL(nal_h264_write_filler); |
554 | |
555 | /** |
556 | * nal_h264_read_filler() - Read filler data RBSP |
557 | * @dev: device pointer |
558 | * @src: buffer with RBSP data that is read |
559 | * @n: maximum size of src that shall be read |
560 | * |
561 | * Read a filler data RBSP from @src up to a maximum size of @n bytes and |
562 | * return the size of the filler data in bytes including the marker. |
563 | * |
564 | * This function is used to parse filler data and skip the respective bytes in |
565 | * the RBSP data. |
566 | * |
567 | * The RBSP format of the filler data is specified in Rec. ITU-T H.264 |
568 | * (04/2017) 7.3.2.7 Filler data RBSP syntax. |
569 | * |
570 | * Return: number of filler data bytes (including marker) or negative error |
571 | */ |
572 | ssize_t nal_h264_read_filler(const struct device *dev, void *src, size_t n) |
573 | { |
574 | struct rbsp rbsp; |
575 | unsigned int forbidden_zero_bit; |
576 | unsigned int nal_ref_idc; |
577 | unsigned int nal_unit_type; |
578 | |
579 | if (!src) |
580 | return -EINVAL; |
581 | |
582 | rbsp_init(rbsp: &rbsp, addr: src, size: n, ops: &read); |
583 | |
584 | nal_h264_read_start_code_prefix(rbsp: &rbsp); |
585 | |
586 | rbsp_bit(rbsp: &rbsp, value: &forbidden_zero_bit); |
587 | rbsp_bits(rbsp: &rbsp, n: 2, value: &nal_ref_idc); |
588 | rbsp_bits(rbsp: &rbsp, n: 5, value: &nal_unit_type); |
589 | |
590 | if (rbsp.error) |
591 | return rbsp.error; |
592 | if (forbidden_zero_bit != 0 || |
593 | nal_ref_idc != 0 || |
594 | nal_unit_type != FILLER_DATA) |
595 | return -EINVAL; |
596 | |
597 | nal_h264_read_filler_data(rbsp: &rbsp); |
598 | rbsp_trailing_bits(rbsp: &rbsp); |
599 | |
600 | if (rbsp.error) |
601 | return rbsp.error; |
602 | |
603 | return DIV_ROUND_UP(rbsp.pos, 8); |
604 | } |
605 | EXPORT_SYMBOL_GPL(nal_h264_read_filler); |
606 | |