// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2019 Pengutronix, Michael Tretter * * Convert NAL units between raw byte sequence payloads (RBSP) and C structs * * The conversion is defined in "ITU-T Rec. H.264 (04/2017) Advanced video * coding for generic audiovisual services". Decoder drivers may use the * parser to parse RBSP from encoded streams and configure the hardware, if * the hardware is not able to parse RBSP itself. Encoder drivers may use the * generator to generate the RBSP for SPS/PPS nal units and add them to the * encoded stream if the hardware does not generate the units. */ #include #include #include #include #include #include #include #include "nal-h264.h" /* * See Rec. ITU-T H.264 (04/2017) Table 7-1 – NAL unit type codes, syntax * element categories, and NAL unit type classes */ enum nal_unit_type { SEQUENCE_PARAMETER_SET = 7, PICTURE_PARAMETER_SET = 8, FILLER_DATA = 12, }; struct rbsp; struct nal_h264_ops { int (*rbsp_bit)(struct rbsp *rbsp, int *val); int (*rbsp_bits)(struct rbsp *rbsp, int n, unsigned int *val); int (*rbsp_uev)(struct rbsp *rbsp, unsigned int *val); int (*rbsp_sev)(struct rbsp *rbsp, int *val); }; /** * struct rbsp - State object for handling a raw byte sequence payload * @data: pointer to the data of the rbsp * @size: maximum size of the data of the rbsp * @pos: current bit position inside the rbsp * @num_consecutive_zeros: number of zeros before @pos * @ops: per datatype functions for interacting with the rbsp * @error: an error occurred while handling the rbsp * * This struct is passed around the various parsing functions and tracks the * current position within the raw byte sequence payload. * * The @ops field allows to separate the operation, i.e., reading/writing a * value from/to that rbsp, from the structure of the NAL unit. This allows to * have a single function for iterating the NAL unit, while @ops has function * pointers for handling each type in the rbsp. */ struct rbsp { u8 *data; size_t size; unsigned int pos; unsigned int num_consecutive_zeros; struct nal_h264_ops *ops; int error; }; static void rbsp_init(struct rbsp *rbsp, void *addr, size_t size, struct nal_h264_ops *ops) { if (!rbsp) return; rbsp->data = addr; rbsp->size = size; rbsp->pos = 0; rbsp->ops = ops; rbsp->error = 0; } /** * nal_h264_profile_from_v4l2() - Get profile_idc for v4l2 h264 profile * @profile: the profile as &enum v4l2_mpeg_video_h264_profile * * Convert the &enum v4l2_mpeg_video_h264_profile to profile_idc as specified * in Rec. ITU-T H.264 (04/2017) A.2. * * Return: the profile_idc for the passed level */ int nal_h264_profile_from_v4l2(enum v4l2_mpeg_video_h264_profile profile) { switch (profile) { case V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE: return 66; case V4L2_MPEG_VIDEO_H264_PROFILE_MAIN: return 77; case V4L2_MPEG_VIDEO_H264_PROFILE_EXTENDED: return 88; case V4L2_MPEG_VIDEO_H264_PROFILE_HIGH: return 100; default: return -EINVAL; } } /** * nal_h264_level_from_v4l2() - Get level_idc for v4l2 h264 level * @level: the level as &enum v4l2_mpeg_video_h264_level * * Convert the &enum v4l2_mpeg_video_h264_level to level_idc as specified in * Rec. ITU-T H.264 (04/2017) A.3.2. * * Return: the level_idc for the passed level */ int nal_h264_level_from_v4l2(enum v4l2_mpeg_video_h264_level level) { switch (level) { case V4L2_MPEG_VIDEO_H264_LEVEL_1_0: return 10; case V4L2_MPEG_VIDEO_H264_LEVEL_1B: return 9; case V4L2_MPEG_VIDEO_H264_LEVEL_1_1: return 11; case V4L2_MPEG_VIDEO_H264_LEVEL_1_2: return 12; case V4L2_MPEG_VIDEO_H264_LEVEL_1_3: return 13; case V4L2_MPEG_VIDEO_H264_LEVEL_2_0: return 20; case V4L2_MPEG_VIDEO_H264_LEVEL_2_1: return 21; case V4L2_MPEG_VIDEO_H264_LEVEL_2_2: return 22; case V4L2_MPEG_VIDEO_H264_LEVEL_3_0: return 30; case V4L2_MPEG_VIDEO_H264_LEVEL_3_1: return 31; case V4L2_MPEG_VIDEO_H264_LEVEL_3_2: return 32; case V4L2_MPEG_VIDEO_H264_LEVEL_4_0: return 40; case V4L2_MPEG_VIDEO_H264_LEVEL_4_1: return 41; case V4L2_MPEG_VIDEO_H264_LEVEL_4_2: return 42; case V4L2_MPEG_VIDEO_H264_LEVEL_5_0: return 50; case V4L2_MPEG_VIDEO_H264_LEVEL_5_1: return 51; default: return -EINVAL; } } static int rbsp_read_bits(struct rbsp *rbsp, int n, unsigned int *value); static int rbsp_write_bits(struct rbsp *rbsp, int n, unsigned int value); /* * When reading or writing, the emulation_prevention_three_byte is detected * only when the 2 one bits need to be inserted. Therefore, we are not * actually adding the 0x3 byte, but the 2 one bits and the six 0 bits of the * next byte. */ #define EMULATION_PREVENTION_THREE_BYTE (0x3 << 6) static int add_emulation_prevention_three_byte(struct rbsp *rbsp) { rbsp->num_consecutive_zeros = 0; rbsp_write_bits(rbsp, 8, EMULATION_PREVENTION_THREE_BYTE); return 0; } static int discard_emulation_prevention_three_byte(struct rbsp *rbsp) { unsigned int tmp = 0; rbsp->num_consecutive_zeros = 0; rbsp_read_bits(rbsp, 8, &tmp); if (tmp != EMULATION_PREVENTION_THREE_BYTE) return -EINVAL; return 0; } static inline int rbsp_read_bit(struct rbsp *rbsp) { int shift; int ofs; int bit; int err; if (rbsp->num_consecutive_zeros == 22) { err = discard_emulation_prevention_three_byte(rbsp); if (err) return err; } shift = 7 - (rbsp->pos % 8); ofs = rbsp->pos / 8; if (ofs >= rbsp->size) return -EINVAL; bit = (rbsp->data[ofs] >> shift) & 1; rbsp->pos++; if (bit == 1 || (rbsp->num_consecutive_zeros < 7 && (rbsp->pos % 8 == 0))) rbsp->num_consecutive_zeros = 0; else rbsp->num_consecutive_zeros++; return bit; } static inline int rbsp_write_bit(struct rbsp *rbsp, bool value) { int shift; int ofs; if (rbsp->num_consecutive_zeros == 22) add_emulation_prevention_three_byte(rbsp); shift = 7 - (rbsp->pos % 8); ofs = rbsp->pos / 8; if (ofs >= rbsp->size) return -EINVAL; rbsp->data[ofs] &= ~(1 << shift); rbsp->data[ofs] |= value << shift; rbsp->pos++; if (value == 1 || (rbsp->num_consecutive_zeros < 7 && (rbsp->pos % 8 == 0))) { rbsp->num_consecutive_zeros = 0; } else { rbsp->num_consecutive_zeros++; } return 0; } static inline int rbsp_read_bits(struct rbsp *rbsp, int n, unsigned int *value) { int i; int bit; unsigned int tmp = 0; if (n > 8 * sizeof(*value)) return -EINVAL; for (i = n; i > 0; i--) { bit = rbsp_read_bit(rbsp); if (bit < 0) return bit; tmp |= bit << (i - 1); } if (value) *value = tmp; return 0; } static int rbsp_write_bits(struct rbsp *rbsp, int n, unsigned int value) { int ret; if (n > 8 * sizeof(value)) return -EINVAL; while (n--) { ret = rbsp_write_bit(rbsp, (value >> n) & 1); if (ret) return ret; } return 0; } static int rbsp_read_uev(struct rbsp *rbsp, unsigned int *value) { int leading_zero_bits = 0; unsigned int tmp = 0; int ret; while ((ret = rbsp_read_bit(rbsp)) == 0) leading_zero_bits++; if (ret < 0) return ret; if (leading_zero_bits > 0) { ret = rbsp_read_bits(rbsp, leading_zero_bits, &tmp); if (ret) return ret; } if (value) *value = (1 << leading_zero_bits) - 1 + tmp; return 0; } static int rbsp_write_uev(struct rbsp *rbsp, unsigned int *value) { int ret; int leading_zero_bits; if (!value) return -EINVAL; leading_zero_bits = ilog2(*value + 1); ret = rbsp_write_bits(rbsp, leading_zero_bits, 0); if (ret) return ret; return rbsp_write_bits(rbsp, leading_zero_bits + 1, *value + 1); } static int rbsp_read_sev(struct rbsp *rbsp, int *value) { int ret; unsigned int tmp; ret = rbsp_read_uev(rbsp, &tmp); if (ret) return ret; if (value) { if (tmp & 1) *value = (tmp + 1) / 2; else *value = -(tmp / 2); } return 0; } static int rbsp_write_sev(struct rbsp *rbsp, int *value) { unsigned int tmp; if (!value) return -EINVAL; if (*value > 0) tmp = (2 * (*value)) | 1; else tmp = -2 * (*value); return rbsp_write_uev(rbsp, &tmp); } static int __rbsp_write_bit(struct rbsp *rbsp, int *value) { return rbsp_write_bit(rbsp, *value); } static int __rbsp_write_bits(struct rbsp *rbsp, int n, unsigned int *value) { return rbsp_write_bits(rbsp, n, *value); } static struct nal_h264_ops write = { .rbsp_bit = __rbsp_write_bit, .rbsp_bits = __rbsp_write_bits, .rbsp_uev = rbsp_write_uev, .rbsp_sev = rbsp_write_sev, }; static int __rbsp_read_bit(struct rbsp *rbsp, int *value) { int tmp = rbsp_read_bit(rbsp); if (tmp < 0) return tmp; *value = tmp; return 0; } static struct nal_h264_ops read = { .rbsp_bit = __rbsp_read_bit, .rbsp_bits = rbsp_read_bits, .rbsp_uev = rbsp_read_uev, .rbsp_sev = rbsp_read_sev, }; static inline void rbsp_bit(struct rbsp *rbsp, int *value) { if (rbsp->error) return; rbsp->error = rbsp->ops->rbsp_bit(rbsp, value); } static inline void rbsp_bits(struct rbsp *rbsp, int n, int *value) { if (rbsp->error) return; rbsp->error = rbsp->ops->rbsp_bits(rbsp, n, value); } static inline void rbsp_uev(struct rbsp *rbsp, unsigned int *value) { if (rbsp->error) return; rbsp->error = rbsp->ops->rbsp_uev(rbsp, value); } static inline void rbsp_sev(struct rbsp *rbsp, int *value) { if (rbsp->error) return; rbsp->error = rbsp->ops->rbsp_sev(rbsp, value); } static void nal_h264_rbsp_trailing_bits(struct rbsp *rbsp) { unsigned int rbsp_stop_one_bit = 1; unsigned int rbsp_alignment_zero_bit = 0; rbsp_bit(rbsp, &rbsp_stop_one_bit); rbsp_bits(rbsp, round_up(rbsp->pos, 8) - rbsp->pos, &rbsp_alignment_zero_bit); } static void nal_h264_write_start_code_prefix(struct rbsp *rbsp) { u8 *p = rbsp->data + DIV_ROUND_UP(rbsp->pos, 8); int i = 4; if (DIV_ROUND_UP(rbsp->pos, 8) + i > rbsp->size) { rbsp->error = -EINVAL; return; } p[0] = 0x00; p[1] = 0x00; p[2] = 0x00; p[3] = 0x01; rbsp->pos += i * 8; } static void nal_h264_read_start_code_prefix(struct rbsp *rbsp) { u8 *p = rbsp->data + DIV_ROUND_UP(rbsp->pos, 8); int i = 4; if (DIV_ROUND_UP(rbsp->pos, 8) + i > rbsp->size) { rbsp->error = -EINVAL; return; } if (p[0] != 0x00 || p[1] != 0x00 || p[2] != 0x00 || p[3] != 0x01) { rbsp->error = -EINVAL; return; } rbsp->pos += i * 8; } static void nal_h264_write_filler_data(struct rbsp *rbsp) { u8 *p = rbsp->data + DIV_ROUND_UP(rbsp->pos, 8); int i; /* Keep 1 byte extra for terminating the NAL unit */ i = rbsp->size - DIV_ROUND_UP(rbsp->pos, 8) - 1; memset(p, 0xff, i); rbsp->pos += i * 8; } static void nal_h264_read_filler_data(struct rbsp *rbsp) { u8 *p = rbsp->data + DIV_ROUND_UP(rbsp->pos, 8); while (*p == 0xff) { if (DIV_ROUND_UP(rbsp->pos, 8) > rbsp->size) { rbsp->error = -EINVAL; return; } p++; rbsp->pos += 8; } } static void nal_h264_rbsp_hrd_parameters(struct rbsp *rbsp, struct nal_h264_hrd_parameters *hrd) { unsigned int i; if (!hrd) { rbsp->error = -EINVAL; return; } rbsp_uev(rbsp, &hrd->cpb_cnt_minus1); rbsp_bits(rbsp, 4, &hrd->bit_rate_scale); rbsp_bits(rbsp, 4, &hrd->cpb_size_scale); for (i = 0; i <= hrd->cpb_cnt_minus1; i++) { rbsp_uev(rbsp, &hrd->bit_rate_value_minus1[i]); rbsp_uev(rbsp, &hrd->cpb_size_value_minus1[i]); rbsp_bit(rbsp, &hrd->cbr_flag[i]); } rbsp_bits(rbsp, 5, &hrd->initial_cpb_removal_delay_length_minus1); rbsp_bits(rbsp, 5, &hrd->cpb_removal_delay_length_minus1); rbsp_bits(rbsp, 5, &hrd->dpb_output_delay_length_minus1); rbsp_bits(rbsp, 5, &hrd->time_offset_length); } static void nal_h264_rbsp_vui_parameters(struct rbsp *rbsp, struct nal_h264_vui_parameters *vui) { if (!vui) { rbsp->error = -EINVAL; return; } rbsp_bit(rbsp, &vui->aspect_ratio_info_present_flag); if (vui->aspect_ratio_info_present_flag) { rbsp_bits(rbsp, 8, &vui->aspect_ratio_idc); if (vui->aspect_ratio_idc == 255) { rbsp_bits(rbsp, 16, &vui->sar_width); rbsp_bits(rbsp, 16, &vui->sar_height); } } rbsp_bit(rbsp, &vui->overscan_info_present_flag); if (vui->overscan_info_present_flag) rbsp_bit(rbsp, &vui->overscan_appropriate_flag); rbsp_bit(rbsp, &vui->video_signal_type_present_flag); if (vui->video_signal_type_present_flag) { rbsp_bits(rbsp, 3, &vui->video_format); rbsp_bit(rbsp, &vui->video_full_range_flag); rbsp_bit(rbsp, &vui->colour_description_present_flag); if (vui->colour_description_present_flag) { rbsp_bits(rbsp, 8, &vui->colour_primaries); rbsp_bits(rbsp, 8, &vui->transfer_characteristics); rbsp_bits(rbsp, 8, &vui->matrix_coefficients); } } rbsp_bit(rbsp, &vui->chroma_loc_info_present_flag); if (vui->chroma_loc_info_present_flag) { rbsp_uev(rbsp, &vui->chroma_sample_loc_type_top_field); rbsp_uev(rbsp, &vui->chroma_sample_loc_type_bottom_field); } rbsp_bit(rbsp, &vui->timing_info_present_flag); if (vui->timing_info_present_flag) { rbsp_bits(rbsp, 32, &vui->num_units_in_tick); rbsp_bits(rbsp, 32, &vui->time_scale); rbsp_bit(rbsp, &vui->fixed_frame_rate_flag); } rbsp_bit(rbsp, &vui->nal_hrd_parameters_present_flag); if (vui->nal_hrd_parameters_present_flag) nal_h264_rbsp_hrd_parameters(rbsp, &vui->nal_hrd_parameters); rbsp_bit(rbsp, &vui->vcl_hrd_parameters_present_flag); if (vui->vcl_hrd_parameters_present_flag) nal_h264_rbsp_hrd_parameters(rbsp, &vui->vcl_hrd_parameters); if (vui->nal_hrd_parameters_present_flag || vui->vcl_hrd_parameters_present_flag) rbsp_bit(rbsp, &vui->low_delay_hrd_flag); rbsp_bit(rbsp, &vui->pic_struct_present_flag); rbsp_bit(rbsp, &vui->bitstream_restriction_flag); if (vui->bitstream_restriction_flag) { rbsp_bit(rbsp, &vui->motion_vectors_over_pic_boundaries_flag); rbsp_uev(rbsp, &vui->max_bytes_per_pic_denom); rbsp_uev(rbsp, &vui->max_bits_per_mb_denom); rbsp_uev(rbsp, &vui->log2_max_mv_length_horizontal); rbsp_uev(rbsp, &vui->log21_max_mv_length_vertical); rbsp_uev(rbsp, &vui->max_num_reorder_frames); rbsp_uev(rbsp, &vui->max_dec_frame_buffering); } } static void nal_h264_rbsp_sps(struct rbsp *rbsp, struct nal_h264_sps *sps) { unsigned int i; if (!sps) { rbsp->error = -EINVAL; return; } rbsp_bits(rbsp, 8, &sps->profile_idc); rbsp_bit(rbsp, &sps->constraint_set0_flag); rbsp_bit(rbsp, &sps->constraint_set1_flag); rbsp_bit(rbsp, &sps->constraint_set2_flag); rbsp_bit(rbsp, &sps->constraint_set3_flag); rbsp_bit(rbsp, &sps->constraint_set4_flag); rbsp_bit(rbsp, &sps->constraint_set5_flag); rbsp_bits(rbsp, 2, &sps->reserved_zero_2bits); rbsp_bits(rbsp, 8, &sps->level_idc); rbsp_uev(rbsp, &sps->seq_parameter_set_id); if (sps->profile_idc == 100 || sps->profile_idc == 110 || sps->profile_idc == 122 || sps->profile_idc == 244 || sps->profile_idc == 44 || sps->profile_idc == 83 || sps->profile_idc == 86 || sps->profile_idc == 118 || sps->profile_idc == 128 || sps->profile_idc == 138 || sps->profile_idc == 139 || sps->profile_idc == 134 || sps->profile_idc == 135) { rbsp_uev(rbsp, &sps->chroma_format_idc); if (sps->chroma_format_idc == 3) rbsp_bit(rbsp, &sps->separate_colour_plane_flag); rbsp_uev(rbsp, &sps->bit_depth_luma_minus8); rbsp_uev(rbsp, &sps->bit_depth_chroma_minus8); rbsp_bit(rbsp, &sps->qpprime_y_zero_transform_bypass_flag); rbsp_bit(rbsp, &sps->seq_scaling_matrix_present_flag); if (sps->seq_scaling_matrix_present_flag) rbsp->error = -EINVAL; } rbsp_uev(rbsp, &sps->log2_max_frame_num_minus4); rbsp_uev(rbsp, &sps->pic_order_cnt_type); switch (sps->pic_order_cnt_type) { case 0: rbsp_uev(rbsp, &sps->log2_max_pic_order_cnt_lsb_minus4); break; case 1: rbsp_bit(rbsp, &sps->delta_pic_order_always_zero_flag); rbsp_sev(rbsp, &sps->offset_for_non_ref_pic); rbsp_sev(rbsp, &sps->offset_for_top_to_bottom_field); rbsp_uev(rbsp, &sps->num_ref_frames_in_pic_order_cnt_cycle); for (i = 0; i < sps->num_ref_frames_in_pic_order_cnt_cycle; i++) rbsp_sev(rbsp, &sps->offset_for_ref_frame[i]); break; default: rbsp->error = -EINVAL; break; } rbsp_uev(rbsp, &sps->max_num_ref_frames); rbsp_bit(rbsp, &sps->gaps_in_frame_num_value_allowed_flag); rbsp_uev(rbsp, &sps->pic_width_in_mbs_minus1); rbsp_uev(rbsp, &sps->pic_height_in_map_units_minus1); rbsp_bit(rbsp, &sps->frame_mbs_only_flag); if (!sps->frame_mbs_only_flag) rbsp_bit(rbsp, &sps->mb_adaptive_frame_field_flag); rbsp_bit(rbsp, &sps->direct_8x8_inference_flag); rbsp_bit(rbsp, &sps->frame_cropping_flag); if (sps->frame_cropping_flag) { rbsp_uev(rbsp, &sps->crop_left); rbsp_uev(rbsp, &sps->crop_right); rbsp_uev(rbsp, &sps->crop_top); rbsp_uev(rbsp, &sps->crop_bottom); } rbsp_bit(rbsp, &sps->vui_parameters_present_flag); if (sps->vui_parameters_present_flag) nal_h264_rbsp_vui_parameters(rbsp, &sps->vui); } static void nal_h264_rbsp_pps(struct rbsp *rbsp, struct nal_h264_pps *pps) { int i; rbsp_uev(rbsp, &pps->pic_parameter_set_id); rbsp_uev(rbsp, &pps->seq_parameter_set_id); rbsp_bit(rbsp, &pps->entropy_coding_mode_flag); rbsp_bit(rbsp, &pps->bottom_field_pic_order_in_frame_present_flag); rbsp_uev(rbsp, &pps->num_slice_groups_minus1); if (pps->num_slice_groups_minus1 > 0) { rbsp_uev(rbsp, &pps->slice_group_map_type); switch (pps->slice_group_map_type) { case 0: for (i = 0; i < pps->num_slice_groups_minus1; i++) rbsp_uev(rbsp, &pps->run_length_minus1[i]); break; case 2: for (i = 0; i < pps->num_slice_groups_minus1; i++) { rbsp_uev(rbsp, &pps->top_left[i]); rbsp_uev(rbsp, &pps->bottom_right[i]); } break; case 3: case 4: case 5: rbsp_bit(rbsp, &pps->slice_group_change_direction_flag); rbsp_uev(rbsp, &pps->slice_group_change_rate_minus1); break; case 6: rbsp_uev(rbsp, &pps->pic_size_in_map_units_minus1); for (i = 0; i < pps->pic_size_in_map_units_minus1; i++) rbsp_bits(rbsp, order_base_2(pps->num_slice_groups_minus1 + 1), &pps->slice_group_id[i]); break; default: break; } } rbsp_uev(rbsp, &pps->num_ref_idx_l0_default_active_minus1); rbsp_uev(rbsp, &pps->num_ref_idx_l1_default_active_minus1); rbsp_bit(rbsp, &pps->weighted_pred_flag); rbsp_bits(rbsp, 2, &pps->weighted_bipred_idc); rbsp_sev(rbsp, &pps->pic_init_qp_minus26); rbsp_sev(rbsp, &pps->pic_init_qs_minus26); rbsp_sev(rbsp, &pps->chroma_qp_index_offset); rbsp_bit(rbsp, &pps->deblocking_filter_control_present_flag); rbsp_bit(rbsp, &pps->constrained_intra_pred_flag); rbsp_bit(rbsp, &pps->redundant_pic_cnt_present_flag); if (/* more_rbsp_data() */ false) { rbsp_bit(rbsp, &pps->transform_8x8_mode_flag); rbsp_bit(rbsp, &pps->pic_scaling_matrix_present_flag); if (pps->pic_scaling_matrix_present_flag) rbsp->error = -EINVAL; rbsp_sev(rbsp, &pps->second_chroma_qp_index_offset); } } /** * nal_h264_write_sps() - Write SPS NAL unit into RBSP format * @dev: device pointer * @dest: the buffer that is filled with RBSP data * @n: maximum size of @dest in bytes * @sps: &struct nal_h264_sps to convert to RBSP * * Convert @sps to RBSP data and write it into @dest. * * The size of the SPS NAL unit is not known in advance and this function will * fail, if @dest does not hold sufficient space for the SPS NAL unit. * * Return: number of bytes written to @dest or negative error code */ ssize_t nal_h264_write_sps(const struct device *dev, void *dest, size_t n, struct nal_h264_sps *sps) { struct rbsp rbsp; unsigned int forbidden_zero_bit = 0; unsigned int nal_ref_idc = 0; unsigned int nal_unit_type = SEQUENCE_PARAMETER_SET; if (!dest) return -EINVAL; rbsp_init(&rbsp, dest, n, &write); nal_h264_write_start_code_prefix(&rbsp); rbsp_bit(&rbsp, &forbidden_zero_bit); rbsp_bits(&rbsp, 2, &nal_ref_idc); rbsp_bits(&rbsp, 5, &nal_unit_type); nal_h264_rbsp_sps(&rbsp, sps); nal_h264_rbsp_trailing_bits(&rbsp); if (rbsp.error) return rbsp.error; return DIV_ROUND_UP(rbsp.pos, 8); } EXPORT_SYMBOL_GPL(nal_h264_write_sps); /** * nal_h264_read_sps() - Read SPS NAL unit from RBSP format * @dev: device pointer * @sps: the &struct nal_h264_sps to fill from the RBSP data * @src: the buffer that contains the RBSP data * @n: size of @src in bytes * * Read RBSP data from @src and use it to fill @sps. * * Return: number of bytes read from @src or negative error code */ ssize_t nal_h264_read_sps(const struct device *dev, struct nal_h264_sps *sps, void *src, size_t n) { struct rbsp rbsp; unsigned int forbidden_zero_bit; unsigned int nal_ref_idc; unsigned int nal_unit_type; if (!src) return -EINVAL; rbsp_init(&rbsp, src, n, &read); nal_h264_read_start_code_prefix(&rbsp); rbsp_bit(&rbsp, &forbidden_zero_bit); rbsp_bits(&rbsp, 2, &nal_ref_idc); rbsp_bits(&rbsp, 5, &nal_unit_type); if (rbsp.error || forbidden_zero_bit != 0 || nal_ref_idc != 0 || nal_unit_type != SEQUENCE_PARAMETER_SET) return -EINVAL; nal_h264_rbsp_sps(&rbsp, sps); nal_h264_rbsp_trailing_bits(&rbsp); if (rbsp.error) return rbsp.error; return DIV_ROUND_UP(rbsp.pos, 8); } EXPORT_SYMBOL_GPL(nal_h264_read_sps); /** * nal_h264_write_pps() - Write PPS NAL unit into RBSP format * @dev: device pointer * @dest: the buffer that is filled with RBSP data * @n: maximum size of @dest in bytes * @pps: &struct nal_h264_pps to convert to RBSP * * Convert @pps to RBSP data and write it into @dest. * * The size of the PPS NAL unit is not known in advance and this function will * fail, if @dest does not hold sufficient space for the PPS NAL unit. * * Return: number of bytes written to @dest or negative error code */ ssize_t nal_h264_write_pps(const struct device *dev, void *dest, size_t n, struct nal_h264_pps *pps) { struct rbsp rbsp; unsigned int forbidden_zero_bit = 0; unsigned int nal_ref_idc = 0; unsigned int nal_unit_type = PICTURE_PARAMETER_SET; if (!dest) return -EINVAL; rbsp_init(&rbsp, dest, n, &write); nal_h264_write_start_code_prefix(&rbsp); /* NAL unit header */ rbsp_bit(&rbsp, &forbidden_zero_bit); rbsp_bits(&rbsp, 2, &nal_ref_idc); rbsp_bits(&rbsp, 5, &nal_unit_type); nal_h264_rbsp_pps(&rbsp, pps); nal_h264_rbsp_trailing_bits(&rbsp); if (rbsp.error) return rbsp.error; return DIV_ROUND_UP(rbsp.pos, 8); } EXPORT_SYMBOL_GPL(nal_h264_write_pps); /** * nal_h264_read_pps() - Read PPS NAL unit from RBSP format * @dev: device pointer * @pps: the &struct nal_h264_pps to fill from the RBSP data * @src: the buffer that contains the RBSP data * @n: size of @src in bytes * * Read RBSP data from @src and use it to fill @pps. * * Return: number of bytes read from @src or negative error code */ ssize_t nal_h264_read_pps(const struct device *dev, struct nal_h264_pps *pps, void *src, size_t n) { struct rbsp rbsp; if (!src) return -EINVAL; rbsp_init(&rbsp, src, n, &read); nal_h264_read_start_code_prefix(&rbsp); /* NAL unit header */ rbsp.pos += 8; nal_h264_rbsp_pps(&rbsp, pps); nal_h264_rbsp_trailing_bits(&rbsp); if (rbsp.error) return rbsp.error; return DIV_ROUND_UP(rbsp.pos, 8); } EXPORT_SYMBOL_GPL(nal_h264_read_pps); /** * nal_h264_write_filler() - Write filler data RBSP * @dev: device pointer * @dest: buffer to fill with filler data * @n: size of the buffer to fill with filler data * * Write a filler data RBSP to @dest with a size of @n bytes and return the * number of written filler data bytes. * * Use this function to generate dummy data in an RBSP data stream that can be * safely ignored by h264 decoders. * * The RBSP format of the filler data is specified in Rec. ITU-T H.264 * (04/2017) 7.3.2.7 Filler data RBSP syntax. * * Return: number of filler data bytes (including marker) or negative error */ ssize_t nal_h264_write_filler(const struct device *dev, void *dest, size_t n) { struct rbsp rbsp; unsigned int forbidden_zero_bit = 0; unsigned int nal_ref_idc = 0; unsigned int nal_unit_type = FILLER_DATA; if (!dest) return -EINVAL; rbsp_init(&rbsp, dest, n, &write); nal_h264_write_start_code_prefix(&rbsp); rbsp_bit(&rbsp, &forbidden_zero_bit); rbsp_bits(&rbsp, 2, &nal_ref_idc); rbsp_bits(&rbsp, 5, &nal_unit_type); nal_h264_write_filler_data(&rbsp); nal_h264_rbsp_trailing_bits(&rbsp); return DIV_ROUND_UP(rbsp.pos, 8); } EXPORT_SYMBOL_GPL(nal_h264_write_filler); /** * nal_h264_read_filler() - Read filler data RBSP * @dev: device pointer * @src: buffer with RBSP data that is read * @n: maximum size of src that shall be read * * Read a filler data RBSP from @src up to a maximum size of @n bytes and * return the size of the filler data in bytes including the marker. * * This function is used to parse filler data and skip the respective bytes in * the RBSP data. * * The RBSP format of the filler data is specified in Rec. ITU-T H.264 * (04/2017) 7.3.2.7 Filler data RBSP syntax. * * Return: number of filler data bytes (including marker) or negative error */ ssize_t nal_h264_read_filler(const struct device *dev, void *src, size_t n) { struct rbsp rbsp; unsigned int forbidden_zero_bit; unsigned int nal_ref_idc; unsigned int nal_unit_type; if (!src) return -EINVAL; rbsp_init(&rbsp, src, n, &read); nal_h264_read_start_code_prefix(&rbsp); rbsp_bit(&rbsp, &forbidden_zero_bit); rbsp_bits(&rbsp, 2, &nal_ref_idc); rbsp_bits(&rbsp, 5, &nal_unit_type); if (rbsp.error) return rbsp.error; if (forbidden_zero_bit != 0 || nal_ref_idc != 0 || nal_unit_type != FILLER_DATA) return -EINVAL; nal_h264_read_filler_data(&rbsp); nal_h264_rbsp_trailing_bits(&rbsp); if (rbsp.error) return rbsp.error; return DIV_ROUND_UP(rbsp.pos, 8); } EXPORT_SYMBOL_GPL(nal_h264_read_filler);