lavc: Add coded bitstream read/write support for H.264

(cherry picked from commit acf06f45441be24c5cbae0920579cd69427326a1)
(cherry picked from commit 768eb9182e94a94bc2ef46f565a0dac7afef3b57)
(cherry picked from commit e7f64191b27bcf37cbf7006606f0f439c6cdc24f)

1 files changed, 1230 insertions, 0 deletions

diff --git a/libavcodec/cbs_h264_syntax_template.c b/libavcodec/cbs_h264_syntax_template.c
new file mode 100644
index 0000000000..8303acbdc4
--- /dev/null
+++ b/libavcodec/cbs_h264_syntax_template.c
@@ -0,0 +1,1230 @@
+/*
+ * 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
+ */
+
+static int FUNC(rbsp_trailing_bits)(CodedBitstreamContext *ctx, RWContext *rw)
+{
+    int err;
+    av_unused int one = 1, zero = 0;
+    xu(1, rbsp_stop_one_bit, one, 1, 1);
+    while (byte_alignment(rw) != 0)
+        xu(1, rbsp_alignment_zero_bit, zero, 0, 0);
+
+    return 0;
+}
+
+static int FUNC(nal_unit_header)(CodedBitstreamContext *ctx, RWContext *rw,
+                                 H264RawNALUnitHeader *current,
+                                 uint32_t valid_type_mask)
+{
+    int err;
+
+    u(1, forbidden_zero_bit, 0, 0);
+    u(2, nal_ref_idc,        0, 3);
+    u(5, nal_unit_type,      0, 31);
+
+    if (!(1 << current->nal_unit_type & valid_type_mask)) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid NAL unit type %d.\n",
+               current->nal_unit_type);
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (current->nal_unit_type == 14 ||
+        current->nal_unit_type == 20 ||
+        current->nal_unit_type == 21) {
+        if (current->nal_unit_type != 21)
+            flag(svc_extension_flag);
+        else
+            flag(avc_3d_extension_flag);
+
+        if (current->svc_extension_flag) {
+            av_log(ctx->log_ctx, AV_LOG_ERROR, "SVC not supported.\n");
+            return AVERROR_PATCHWELCOME;
+
+        } else if (current->avc_3d_extension_flag) {
+            av_log(ctx->log_ctx, AV_LOG_ERROR, "3DAVC not supported.\n");
+            return AVERROR_PATCHWELCOME;
+
+        } else {
+            av_log(ctx->log_ctx, AV_LOG_ERROR, "MVC not supported.\n");
+            return AVERROR_PATCHWELCOME;
+        }
+    }
+
+    return 0;
+}
+
+static int FUNC(scaling_list)(CodedBitstreamContext *ctx, RWContext *rw,
+                              H264RawScalingList *current,
+                              int size_of_scaling_list)
+{
+    int err, i, scale;
+
+    scale = 8;
+    for (i = 0; i < size_of_scaling_list; i++) {
+        xse(delta_scale, current->delta_scale[i], -128, +127);
+        scale = (scale + current->delta_scale[i] + 256) % 256;
+        if (scale == 0)
+            break;
+    }
+
+    return 0;
+}
+
+static int FUNC(hrd_parameters)(CodedBitstreamContext *ctx, RWContext *rw,
+                                H264RawHRD *current)
+{
+    int err, i;
+
+    ue(cpb_cnt_minus1, 0, 31);
+    u(4, bit_rate_scale, 0, 15);
+    u(4, cpb_size_scale, 0, 15);
+
+    for (i = 0; i <= current->cpb_cnt_minus1; i++) {
+        ue(bit_rate_value_minus1[i], 0, UINT32_MAX - 1);
+        ue(cpb_size_value_minus1[i], 0, UINT32_MAX - 1);
+        flag(cbr_flag[i]);
+    }
+
+    u(5, initial_cpb_removal_delay_length_minus1, 0, 31);
+    u(5, cpb_removal_delay_length_minus1,         0, 31);
+    u(5, dpb_output_delay_length_minus1,          0, 31);
+    u(5, time_offset_length,                      0, 31);
+
+    return 0;
+}
+
+static int FUNC(vui_parameters)(CodedBitstreamContext *ctx, RWContext *rw,
+                                H264RawVUI *current, H264RawSPS *sps)
+{
+    int err;
+
+    flag(aspect_ratio_info_present_flag);
+    if (current->aspect_ratio_info_present_flag) {
+        u(8, aspect_ratio_idc, 0, 255);
+        if (current->aspect_ratio_idc == 255) {
+            u(16, sar_width,  0, 65535);
+            u(16, sar_height, 0, 65535);
+        }
+    } else {
+        infer(aspect_ratio_idc, 0);
+    }
+
+    flag(overscan_info_present_flag);
+    if (current->overscan_info_present_flag)
+        flag(overscan_appropriate_flag);
+
+    flag(video_signal_type_present_flag);
+    if (current->video_signal_type_present_flag) {
+        u(3, video_format, 0, 7);
+        flag(video_full_range_flag);
+        flag(colour_description_present_flag);
+        if (current->colour_description_present_flag) {
+            u(8, colour_primaries,         0, 255);
+            u(8, transfer_characteristics, 0, 255);
+            u(8, matrix_coefficients,      0, 255);
+        }
+    } else {
+        infer(video_format,             5);
+        infer(video_full_range_flag,    0);
+        infer(colour_primaries,         2);
+        infer(transfer_characteristics, 2);
+        infer(matrix_coefficients,      2);
+    }
+
+    flag(chroma_loc_info_present_flag);
+    if (current->chroma_loc_info_present_flag) {
+        ue(chroma_sample_loc_type_top_field,    0, 5);
+        ue(chroma_sample_loc_type_bottom_field, 0, 5);
+    } else {
+        infer(chroma_sample_loc_type_top_field,    0);
+        infer(chroma_sample_loc_type_bottom_field, 0);
+    }
+
+    flag(timing_info_present_flag);
+    if (current->timing_info_present_flag) {
+        u(32, num_units_in_tick, 1, UINT32_MAX);
+        u(32, time_scale,        1, UINT32_MAX);
+        flag(fixed_frame_rate_flag);
+    } else {
+        infer(fixed_frame_rate_flag, 0);
+    }
+
+    flag(nal_hrd_parameters_present_flag);
+    if (current->nal_hrd_parameters_present_flag)
+        CHECK(FUNC(hrd_parameters)(ctx, rw, &current->nal_hrd_parameters));
+
+    flag(vcl_hrd_parameters_present_flag);
+    if (current->vcl_hrd_parameters_present_flag)
+        CHECK(FUNC(hrd_parameters)(ctx, rw, &current->vcl_hrd_parameters));
+
+    if (current->nal_hrd_parameters_present_flag ||
+        current->vcl_hrd_parameters_present_flag)
+        flag(low_delay_hrd_flag);
+    else
+        infer(low_delay_hrd_flag, 1 - current->fixed_frame_rate_flag);
+
+    flag(pic_struct_present_flag);
+
+    flag(bitstream_restriction_flag);
+    if (current->bitstream_restriction_flag) {
+        flag(motion_vectors_over_pic_boundaries_flag);
+        ue(max_bytes_per_pic_denom, 0, 16);
+        ue(max_bits_per_mb_denom,   0, 16);
+        ue(log2_max_mv_length_horizontal, 0, 16);
+        ue(log2_max_mv_length_vertical,   0, 16);
+        ue(max_num_reorder_frames,  0, H264_MAX_DPB_FRAMES);
+        ue(max_dec_frame_buffering, 0, H264_MAX_DPB_FRAMES);
+    } else {
+        infer(motion_vectors_over_pic_boundaries_flag, 1);
+        infer(max_bytes_per_pic_denom, 2);
+        infer(max_bits_per_mb_denom,   1);
+        infer(log2_max_mv_length_horizontal, 16);
+        infer(log2_max_mv_length_vertical,   16);
+
+        if ((sps->profile_idc ==  44 || sps->profile_idc ==  86 ||
+             sps->profile_idc == 110 || sps->profile_idc == 110 ||
+             sps->profile_idc == 122 || sps->profile_idc == 244) &&
+            sps->constraint_set3_flag) {
+            infer(max_num_reorder_frames,  0);
+            infer(max_dec_frame_buffering, 0);
+        } else {
+            infer(max_num_reorder_frames,  H264_MAX_DPB_FRAMES);
+            infer(max_dec_frame_buffering, H264_MAX_DPB_FRAMES);
+        }
+    }
+
+    return 0;
+}
+
+static int FUNC(sps)(CodedBitstreamContext *ctx, RWContext *rw,
+                     H264RawSPS *current)
+{
+    int err, i;
+
+    HEADER("Sequence Parameter Set");
+
+    CHECK(FUNC(nal_unit_header)(ctx, rw, &current->nal_unit_header,
+                                1 << H264_NAL_SPS));
+
+    u(8, profile_idc, 0, 255);
+
+    flag(constraint_set0_flag);
+    flag(constraint_set1_flag);
+    flag(constraint_set2_flag);
+    flag(constraint_set3_flag);
+    flag(constraint_set4_flag);
+    flag(constraint_set5_flag);
+
+    u(2, reserved_zero_2bits,  0, 0);
+
+    u(8, level_idc, 0, 255);
+
+    ue(seq_parameter_set_id, 0, 31);
+
+    if (current->profile_idc == 100 || current->profile_idc == 110 ||
+        current->profile_idc == 122 || current->profile_idc == 244 ||
+        current->profile_idc ==  44 || current->profile_idc ==  83 ||
+        current->profile_idc ==  86 || current->profile_idc == 118 ||
+        current->profile_idc == 128 || current->profile_idc == 138) {
+        ue(chroma_format_idc, 0, 3);
+
+        if (current->chroma_format_idc == 3)
+            flag(separate_colour_plane_flag);
+        else
+            infer(separate_colour_plane_flag, 0);
+
+        ue(bit_depth_luma_minus8,   0, 6);
+        ue(bit_depth_chroma_minus8, 0, 6);
+
+        flag(qpprime_y_zero_transform_bypass_flag);
+
+        flag(seq_scaling_matrix_present_flag);
+        if (current->seq_scaling_matrix_present_flag) {
+            for (i = 0; i < ((current->chroma_format_idc != 3) ? 8 : 12); i++) {
+                flag(seq_scaling_list_present_flag[i]);
+                if (current->seq_scaling_list_present_flag[i]) {
+                    if (i < 6)
+                        CHECK(FUNC(scaling_list)(ctx, rw,
+                                                 &current->scaling_list_4x4[i],
+                                                 16));
+                    else
+                        CHECK(FUNC(scaling_list)(ctx, rw,
+                                                 &current->scaling_list_8x8[i - 6],
+                                                 64));
+                }
+            }
+        }
+    } else {
+        infer(chroma_format_idc, current->profile_idc == 183 ? 0 : 1);
+
+        infer(separate_colour_plane_flag, 0);
+        infer(bit_depth_luma_minus8,      0);
+        infer(bit_depth_chroma_minus8,    0);
+    }
+
+    ue(log2_max_frame_num_minus4, 0, 12);
+    ue(pic_order_cnt_type, 0, 2);
+
+    if (current->pic_order_cnt_type == 0) {
+        ue(log2_max_pic_order_cnt_lsb_minus4, 0, 12);
+    } else if (current->pic_order_cnt_type == 1) {
+        flag(delta_pic_order_always_zero_flag);
+        se(offset_for_non_ref_pic,         INT32_MIN + 1, INT32_MAX);
+        se(offset_for_top_to_bottom_field, INT32_MIN + 1, INT32_MAX);
+        ue(num_ref_frames_in_pic_order_cnt_cycle, 0, 255);
+
+        for (i = 0; i < current->num_ref_frames_in_pic_order_cnt_cycle; i++)
+            se(offset_for_ref_frame[i], INT32_MIN + 1, INT32_MAX);
+    }
+
+    ue(max_num_ref_frames, 0, H264_MAX_DPB_FRAMES);
+    flag(gaps_in_frame_num_allowed_flag);
+
+    ue(pic_width_in_mbs_minus1,        0, H264_MAX_MB_WIDTH);
+    ue(pic_height_in_map_units_minus1, 0, H264_MAX_MB_HEIGHT);
+
+    flag(frame_mbs_only_flag);
+    if (!current->frame_mbs_only_flag)
+        flag(mb_adaptive_frame_field_flag);
+
+    flag(direct_8x8_inference_flag);
+
+    flag(frame_cropping_flag);
+    if (current->frame_cropping_flag) {
+        ue(frame_crop_left_offset,   0, H264_MAX_WIDTH);
+        ue(frame_crop_right_offset,  0, H264_MAX_WIDTH);
+        ue(frame_crop_top_offset,    0, H264_MAX_HEIGHT);
+        ue(frame_crop_bottom_offset, 0, H264_MAX_HEIGHT);
+    }
+
+    flag(vui_parameters_present_flag);
+    if (current->vui_parameters_present_flag)
+        CHECK(FUNC(vui_parameters)(ctx, rw, &current->vui, current));
+
+    CHECK(FUNC(rbsp_trailing_bits)(ctx, rw));
+
+    return 0;
+}
+
+static int FUNC(sps_extension)(CodedBitstreamContext *ctx, RWContext *rw,
+                               H264RawSPSExtension *current)
+{
+    int err;
+
+    HEADER("Sequence Parameter Set Extension");
+
+    CHECK(FUNC(nal_unit_header)(ctx, rw, &current->nal_unit_header,
+                                1 << H264_NAL_SPS_EXT));
+
+    ue(seq_parameter_set_id, 0, 31);
+
+    ue(aux_format_idc, 0, 3);
+
+    if (current->aux_format_idc != 0) {
+        int bits;
+
+        ue(bit_depth_aux_minus8, 0, 4);
+        flag(alpha_incr_flag);
+
+        bits = current->bit_depth_aux_minus8 + 9;
+        u(bits, alpha_opaque_value,      0, (1 << bits) - 1);
+        u(bits, alpha_transparent_value, 0, (1 << bits) - 1);
+    }
+
+    flag(additional_extension_flag);
+
+    CHECK(FUNC(rbsp_trailing_bits)(ctx, rw));
+
+    return 0;
+}
+
+static int FUNC(pps)(CodedBitstreamContext *ctx, RWContext *rw,
+                     H264RawPPS *current)
+{
+    CodedBitstreamH264Context *h264 = ctx->priv_data;
+    const H264RawSPS *sps;
+    int err, i;
+
+    HEADER("Picture Parameter Set");
+
+    CHECK(FUNC(nal_unit_header)(ctx, rw, &current->nal_unit_header,
+                                1 << H264_NAL_PPS));
+
+    ue(pic_parameter_set_id, 0, 255);
+    ue(seq_parameter_set_id, 0, 31);
+
+    sps = h264->sps[current->seq_parameter_set_id];
+    if (!sps) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR, "SPS id %d not available.\n",
+               current->seq_parameter_set_id);
+        return AVERROR_INVALIDDATA;
+    }
+
+    flag(entropy_coding_mode_flag);
+    flag(bottom_field_pic_order_in_frame_present_flag);
+
+    ue(num_slice_groups_minus1, 0, 7);
+    if (current->num_slice_groups_minus1 > 0) {
+        unsigned int pic_size;
+        int iGroup;
+
+        pic_size = (sps->pic_width_in_mbs_minus1 + 1) *
+                   (sps->pic_height_in_map_units_minus1 + 1);
+
+        ue(slice_group_map_type, 0, 6);
+
+        if (current->slice_group_map_type == 0) {
+            for (iGroup = 0; iGroup <= current->num_slice_groups_minus1; iGroup++)
+                ue(run_length_minus1[iGroup], 0, pic_size - 1);
+
+        } else if (current->slice_group_map_type == 2) {
+            for (iGroup = 0; iGroup < current->num_slice_groups_minus1; iGroup++) {
+                ue(top_left[iGroup],     0,                         pic_size - 1);
+                ue(bottom_right[iGroup], current->top_left[iGroup], pic_size - 1);
+            }
+        } else if (current->slice_group_map_type == 3 ||
+                   current->slice_group_map_type == 4 ||
+                   current->slice_group_map_type == 5) {
+            flag(slice_group_change_direction_flag);
+            ue(slice_group_change_rate_minus1, 0, pic_size - 1);
+        } else if (current->slice_group_map_type == 6) {
+            ue(pic_size_in_map_units_minus1, pic_size - 1, pic_size - 1);
+            for (i = 0; i <= current->pic_size_in_map_units_minus1; i++)
+                u(av_log2(2 * current->num_slice_groups_minus1 + 1),
+                  slice_group_id[i], 0, current->num_slice_groups_minus1);
+        }
+    }
+
+    ue(num_ref_idx_l0_default_active_minus1, 0, 31);
+    ue(num_ref_idx_l1_default_active_minus1, 0, 31);
+
+    flag(weighted_pred_flag);
+    u(2, weighted_bipred_idc, 0, 2);
+
+    se(pic_init_qp_minus26, -26 - 6 * sps->bit_depth_luma_minus8, +25);
+    se(pic_init_qs_minus26, -26, +25);
+    se(chroma_qp_index_offset, -12, +12);
+
+    flag(deblocking_filter_control_present_flag);
+    flag(constrained_intra_pred_flag);
+    flag(redundant_pic_cnt_present_flag);
+
+    if (more_rbsp_data(current->more_rbsp_data))
+    {
+        flag(transform_8x8_mode_flag);
+
+        flag(pic_scaling_matrix_present_flag);
+        if (current->pic_scaling_matrix_present_flag) {
+            for (i = 0; i < 6 + (((sps->chroma_format_idc != 3) ? 2 : 6) *
+                                 current->transform_8x8_mode_flag); i++) {
+                flag(pic_scaling_list_present_flag[i]);
+                if (current->pic_scaling_list_present_flag[i]) {
+                    if (i < 6)
+                        CHECK(FUNC(scaling_list)(ctx, rw,
+                                                 &current->scaling_list_4x4[i],
+                                                 16));
+                    else
+                        CHECK(FUNC(scaling_list)(ctx, rw,
+                                                 &current->scaling_list_8x8[i - 6],
+                                                 64));
+                }
+            }
+        }
+
+        se(second_chroma_qp_index_offset, -12, +12);
+    } else {
+        infer(transform_8x8_mode_flag, 0);
+        infer(pic_scaling_matrix_present_flag, 0);
+        infer(second_chroma_qp_index_offset, current->chroma_qp_index_offset);
+    }
+
+    CHECK(FUNC(rbsp_trailing_bits)(ctx, rw));
+
+    return 0;
+}
+
+static int FUNC(sei_buffering_period)(CodedBitstreamContext *ctx, RWContext *rw,
+                                      H264RawSEIBufferingPeriod *current)
+{
+    CodedBitstreamH264Context *h264 = ctx->priv_data;
+    const H264RawSPS *sps;
+    int err, i, length;
+
+    ue(seq_parameter_set_id, 0, 31);
+
+    sps = h264->sps[current->seq_parameter_set_id];
+    if (!sps) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR, "SPS id %d not available.\n",
+               current->seq_parameter_set_id);
+        return AVERROR_INVALIDDATA;
+    }
+    h264->active_sps = sps;
+
+    if (sps->vui.nal_hrd_parameters_present_flag) {
+        for (i = 0; i <= sps->vui.nal_hrd_parameters.cpb_cnt_minus1; i++) {
+            length = sps->vui.nal_hrd_parameters.initial_cpb_removal_delay_length_minus1 + 1;
+            xu(length, initial_cpb_removal_delay[SchedSelIdx],
+               current->nal.initial_cpb_removal_delay[i],
+               0, (1 << (uint64_t)length) - 1);
+            xu(length, initial_cpb_removal_delay_offset[SchedSelIdx],
+               current->nal.initial_cpb_removal_delay_offset[i],
+               0, (1 << (uint64_t)length) - 1);
+        }
+    }
+
+    if (sps->vui.vcl_hrd_parameters_present_flag) {
+        for (i = 0; i <= sps->vui.vcl_hrd_parameters.cpb_cnt_minus1; i++) {
+            length = sps->vui.vcl_hrd_parameters.initial_cpb_removal_delay_length_minus1 + 1;
+            xu(length, initial_cpb_removal_delay[SchedSelIdx],
+               current->vcl.initial_cpb_removal_delay[i],
+               0, (1 << (uint64_t)length) - 1);
+            xu(length, initial_cpb_removal_delay_offset[SchedSelIdx],
+               current->vcl.initial_cpb_removal_delay_offset[i],
+               0, (1 << (uint64_t)length) - 1);
+        }
+    }
+
+    return 0;
+}
+
+static int FUNC(sei_pic_timestamp)(CodedBitstreamContext *ctx, RWContext *rw,
+                                   H264RawSEIPicTimestamp *current)
+{
+    CodedBitstreamH264Context *h264 = ctx->priv_data;
+    const H264RawSPS *sps;
+    uint8_t time_offset_length;
+    int err;
+
+    u(2, ct_type, 0, 2);
+    flag(nuit_field_based_flag);
+    u(5, counting_type, 0, 6);
+    flag(full_timestamp_flag);
+    flag(discontinuity_flag);
+    flag(cnt_dropped_flag);
+    u(8, n_frames, 0, 255);
+    if (current->full_timestamp_flag) {
+            u(6, seconds_value, 0, 59);
+            u(6, minutes_value, 0, 59);
+            u(5, hours_value,   0, 23);
+    } else {
+        flag(seconds_flag);
+        if (current->seconds_flag) {
+            u(6, seconds_value, 0, 59);
+            flag(minutes_flag);
+            if (current->minutes_flag) {
+                u(6, minutes_value, 0, 59);
+                flag(hours_flag);
+                if (current->hours_flag)
+                    u(5, hours_value, 0, 23);
+            }
+        }
+    }
+
+    sps = h264->active_sps;
+    if (sps->vui.nal_hrd_parameters_present_flag)
+        time_offset_length = sps->vui.nal_hrd_parameters.time_offset_length;
+    else if (sps->vui.vcl_hrd_parameters_present_flag)
+        time_offset_length = sps->vui.vcl_hrd_parameters.time_offset_length;
+    else
+        time_offset_length = 24;
+
+    if (time_offset_length > 0)
+        u(time_offset_length, time_offset,
+          0, (1 << (uint64_t)time_offset_length) - 1);
+    else
+        infer(time_offset, 0);
+
+    return 0;
+}
+
+static int FUNC(sei_pic_timing)(CodedBitstreamContext *ctx, RWContext *rw,
+                                H264RawSEIPicTiming *current)
+{
+    CodedBitstreamH264Context *h264 = ctx->priv_data;
+    const H264RawSPS *sps;
+    int err;
+
+    sps = h264->active_sps;
+    if (!sps) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR,
+               "No active SPS for pic_timing.\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (sps->vui.nal_hrd_parameters_present_flag ||
+        sps->vui.vcl_hrd_parameters_present_flag) {
+        const H264RawHRD *hrd;
+
+        if (sps->vui.nal_hrd_parameters_present_flag)
+            hrd = &sps->vui.nal_hrd_parameters;
+        else if (sps->vui.vcl_hrd_parameters_present_flag)
+            hrd = &sps->vui.vcl_hrd_parameters;
+        else {
+            av_log(ctx->log_ctx, AV_LOG_ERROR,
+                   "No HRD parameters for pic_timing.\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        u(hrd->cpb_removal_delay_length_minus1 + 1, cpb_removal_delay,
+          0, (1 << (uint64_t)hrd->cpb_removal_delay_length_minus1) + 1);
+        u(hrd->dpb_output_delay_length_minus1 + 1, dpb_output_delay,
+          0, (1 << (uint64_t)hrd->dpb_output_delay_length_minus1) + 1);
+    }
+
+    if (sps->vui.pic_struct_present_flag) {
+        static const int num_clock_ts[9] = {
+            1, 1, 1, 2, 2, 3, 3, 2, 3
+        };
+        int i;
+
+        u(4, pic_struct, 0, 8);
+        if (current->pic_struct > 8)
+            return AVERROR_INVALIDDATA;
+
+        for (i = 0; i < num_clock_ts[current->pic_struct]; i++) {
+            flag(clock_timestamp_flag[i]);
+            if (current->clock_timestamp_flag[i])
+                CHECK(FUNC(sei_pic_timestamp)(ctx, rw, &current->timestamp[i]));
+        }
+    }
+
+    return 0;
+}
+
+static int FUNC(sei_user_data_registered)(CodedBitstreamContext *ctx, RWContext *rw,
+                                          H264RawSEIUserDataRegistered *current,
+                                          uint32_t *payload_size)
+{
+    int err, i, j;
+
+    u(8, itu_t_t35_country_code, 0x00, 0xff);
+    if (current->itu_t_t35_country_code != 0xff)
+        i = 1;
+    else {
+        u(8, itu_t_t35_country_code_extension_byte, 0x00, 0xff);
+        i = 2;
+    }
+
+#ifdef READ
+    if (*payload_size < i) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR,
+               "Invalid SEI user data registered payload.\n");
+        return AVERROR_INVALIDDATA;
+    }
+    current->data_length = *payload_size - i;
+#else
+    *payload_size = i + current->data_length;
+#endif
+
+    allocate(current->data, current->data_length);
+    for (j = 0; j < current->data_length; j++)
+        xu(8, itu_t_t35_payload_byte, current->data[j], 0x00, 0xff);
+
+    return 0;
+}
+
+static int FUNC(sei_user_data_unregistered)(CodedBitstreamContext *ctx, RWContext *rw,
+                                            H264RawSEIUserDataUnregistered *current,
+                                            uint32_t *payload_size)
+{
+    int err, i;
+
+#ifdef READ
+    if (*payload_size < 16) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR,
+               "Invalid SEI user data unregistered payload.\n");
+        return AVERROR_INVALIDDATA;
+    }
+    current->data_length = *payload_size - 16;
+#else
+    *payload_size = 16 + current->data_length;
+#endif
+
+    for (i = 0; i < 16; i++) {
+        xu(8, uuid_iso_iec_11578,
+           current->uuid_iso_iec_11578[i], 0x00, 0xff);
+    }
+
+    allocate(current->data, current->data_length);
+
+    for (i = 0; i < current->data_length; i++)
+        xu(8, user_data_payload_byte, current->data[i], 0x00, 0xff);
+
+    return 0;
+}
+
+static int FUNC(sei_recovery_point)(CodedBitstreamContext *ctx, RWContext *rw,
+                                    H264RawSEIRecoveryPoint *current)
+{
+    int err;
+
+    ue(recovery_frame_cnt, 0, 65535);
+    flag(exact_match_flag);
+    flag(broken_link_flag);
+    u(2, changing_slice_group_idc, 0, 2);
+
+    return 0;
+}
+
+static int FUNC(sei_display_orientation)(CodedBitstreamContext *ctx, RWContext *rw,
+                                         H264RawSEIDisplayOrientation *current)
+{
+    int err;
+
+    flag(display_orientation_cancel_flag);
+    if (!current->display_orientation_cancel_flag) {
+        flag(hor_flip);
+        flag(ver_flip);
+        u(16, anticlockwise_rotation, 0, 65535);
+        ue(display_orientation_repetition_period, 0, 16384);
+        flag(display_orientation_extension_flag);
+    }
+
+    return 0;
+}
+
+static int FUNC(sei_payload)(CodedBitstreamContext *ctx, RWContext *rw,
+                             H264RawSEIPayload *current)
+{
+    int err, i;
+    int start_position, end_position;
+
+#ifdef READ
+    start_position = get_bits_count(rw);
+#else
+    start_position = put_bits_count(rw);
+#endif
+
+    switch (current->payload_type) {
+    case H264_SEI_TYPE_BUFFERING_PERIOD:
+        CHECK(FUNC(sei_buffering_period)
+              (ctx, rw, &current->payload.buffering_period));
+        break;
+    case H264_SEI_TYPE_PIC_TIMING:
+        CHECK(FUNC(sei_pic_timing)
+              (ctx, rw, &current->payload.pic_timing));
+        break;
+    case H264_SEI_TYPE_FILLER_PAYLOAD:
+        {
+            av_unused int ff_byte = 0xff;
+            for (i = 0; i  < current->payload_size; i++)
+                xu(8, ff_byte, ff_byte, 0xff, 0xff);
+        }
+        break;
+    case H264_SEI_TYPE_USER_DATA_REGISTERED:
+        CHECK(FUNC(sei_user_data_registered)
+              (ctx, rw, &current->payload.user_data_registered, &current->payload_size));
+        break;
+    case H264_SEI_TYPE_USER_DATA_UNREGISTERED:
+        CHECK(FUNC(sei_user_data_unregistered)
+              (ctx, rw, &current->payload.user_data_unregistered, &current->payload_size));
+        break;
+    case H264_SEI_TYPE_RECOVERY_POINT:
+        CHECK(FUNC(sei_recovery_point)
+              (ctx, rw, &current->payload.recovery_point));
+        break;
+    case H264_SEI_TYPE_DISPLAY_ORIENTATION:
+        CHECK(FUNC(sei_display_orientation)
+              (ctx, rw, &current->payload.display_orientation));
+        break;
+    default:
+        {
+            allocate(current->payload.other.data, current->payload_size);
+            for (i = 0; i < current->payload_size; i++)
+                xu(8, payload_byte, current->payload.other.data[i], 0, 255);
+        }
+    }
+
+    if (byte_alignment(rw)) {
+        av_unused int one = 1, zero = 0;
+        xu(1, bit_equal_to_one, one, 1, 1);
+        while (byte_alignment(rw))
+            xu(1, bit_equal_to_zero, zero, 0, 0);
+    }
+
+#ifdef READ
+    end_position = get_bits_count(rw);
+    if (end_position < start_position + 8 * current->payload_size) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR, "Incorrect SEI payload length: "
+               "header %d bits, actually %d bits.\n",
+               8 * current->payload_size,
+               end_position - start_position);
+        return AVERROR_INVALIDDATA;
+    }
+#else
+    end_position = put_bits_count(rw);
+    current->payload_size = (end_position - start_position) / 8;
+#endif
+
+    return 0;
+}
+
+static int FUNC(sei)(CodedBitstreamContext *ctx, RWContext *rw,
+                     H264RawSEI *current)
+{
+    int err, k;
+
+    HEADER("Supplemental Enhancement Information");
+
+    CHECK(FUNC(nal_unit_header)(ctx, rw, &current->nal_unit_header,
+                                1 << H264_NAL_SEI));
+
+#ifdef READ
+    for (k = 0; k < H264_MAX_SEI_PAYLOADS; k++) {
+        uint32_t payload_type = 0;
+        uint32_t payload_size = 0;
+        uint32_t tmp;
+
+        while (show_bits(rw, 8) == 0xff) {
+            xu(8, ff_byte, tmp, 0xff, 0xff);
+            payload_type += 255;
+        }
+        xu(8, last_payload_type_byte, tmp, 0, 254);
+        payload_type += tmp;
+
+        while (show_bits(rw, 8) == 0xff) {
+            xu(8, ff_byte, tmp, 0xff, 0xff);
+            payload_size += 255;
+        }
+        xu(8, last_payload_size_byte, tmp, 0, 254);
+        payload_size += tmp;
+
+        current->payload[k].payload_type = payload_type;
+        current->payload[k].payload_size = payload_size;
+
+        CHECK(FUNC(sei_payload)(ctx, rw, &current->payload[k]));
+
+        if (!cbs_h2645_read_more_rbsp_data(rw))
+            break;
+    }
+    if (k >= H264_MAX_SEI_PAYLOADS) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR, "Too many payloads in "
+               "SEI message: found %d.\n", k);
+        return AVERROR_INVALIDDATA;
+    }
+    current->payload_count = k + 1;
+#else
+    for (k = 0; k < current->payload_count; k++) {
+        PutBitContext start_state;
+        uint32_t tmp;
+        int need_size, i;
+
+        // Somewhat clumsy: we write the payload twice when
+        // we don't know the size in advance.  This will mess
+        // with trace output, but is otherwise harmless.
+        start_state = *rw;
+        need_size = !current->payload[k].payload_size;
+        for (i = 0; i < 1 + need_size; i++) {
+            *rw = start_state;
+
+            tmp = current->payload[k].payload_type;
+            while (tmp >= 255) {
+                xu(8, ff_byte, 0xff, 0xff, 0xff);
+                tmp -= 255;
+            }
+            xu(8, last_payload_type_byte, tmp, 0, 254);
+
+            tmp = current->payload[k].payload_size;
+            while (tmp >= 255) {
+                xu(8, ff_byte, 0xff, 0xff, 0xff);
+                tmp -= 255;
+            }
+            xu(8, last_payload_size_byte, tmp, 0, 254);
+
+            CHECK(FUNC(sei_payload)(ctx, rw, &current->payload[k]));
+        }
+    }
+#endif
+
+    CHECK(FUNC(rbsp_trailing_bits)(ctx, rw));
+
+    return 0;
+}
+
+static int FUNC(aud)(CodedBitstreamContext *ctx, RWContext *rw,
+                     H264RawAUD *current)
+{
+    int err;
+
+    HEADER("Access Unit Delimiter");
+
+    CHECK(FUNC(nal_unit_header)(ctx, rw, &current->nal_unit_header,
+                                1 << H264_NAL_AUD));
+
+    u(3, primary_pic_type, 0, 7);
+
+    CHECK(FUNC(rbsp_trailing_bits)(ctx, rw));
+
+    return 0;
+}
+
+static int FUNC(ref_pic_list_modification)(CodedBitstreamContext *ctx, RWContext *rw,
+                                           H264RawSliceHeader *current)
+{
+    CodedBitstreamH264Context *h264 = ctx->priv_data;
+    const H264RawSPS *sps = h264->active_sps;
+    int err, i, mopn;
+
+    if (current->slice_type % 5 != 2 &&
+        current->slice_type % 5 != 4) {
+        flag(ref_pic_list_modification_flag_l0);
+        if (current->ref_pic_list_modification_flag_l0) {
+            for (i = 0; i < H264_MAX_RPLM_COUNT; i++) {
+                xue(modification_of_pic_nums_idc,
+                    current->rplm_l0[i].modification_of_pic_nums_idc, 0, 3);
+
+                mopn = current->rplm_l0[i].modification_of_pic_nums_idc;
+                if (mopn == 3)
+                    break;
+
+                if (mopn == 0 || mopn == 1)
+                    xue(abs_diff_pic_num_minus1,
+                        current->rplm_l0[i].abs_diff_pic_num_minus1,
+                        0, (1 + current->field_pic_flag) *
+                        (1 << (sps->log2_max_frame_num_minus4 + 4)));
+                else if (mopn == 2)
+                    xue(long_term_pic_num,
+                        current->rplm_l0[i].long_term_pic_num,
+                        0, sps->max_num_ref_frames - 1);
+            }
+        }
+    }
+
+    if (current->slice_type % 5 == 1) {
+        flag(ref_pic_list_modification_flag_l1);
+        if (current->ref_pic_list_modification_flag_l1) {
+            for (i = 0; i < H264_MAX_RPLM_COUNT; i++) {
+                xue(modification_of_pic_nums_idc,
+                    current->rplm_l1[i].modification_of_pic_nums_idc, 0, 3);
+
+                mopn = current->rplm_l1[i].modification_of_pic_nums_idc;
+                if (mopn == 3)
+                    break;
+
+                if (mopn == 0 || mopn == 1)
+                    xue(abs_diff_pic_num_minus1,
+                        current->rplm_l1[i].abs_diff_pic_num_minus1,
+                        0, (1 + current->field_pic_flag) *
+                        (1 << (sps->log2_max_frame_num_minus4 + 4)));
+                else if (mopn == 2)
+                    xue(long_term_pic_num,
+                        current->rplm_l1[i].long_term_pic_num,
+                        0, sps->max_num_ref_frames - 1);
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int FUNC(pred_weight_table)(CodedBitstreamContext *ctx, RWContext *rw,
+                                   H264RawSliceHeader *current)
+{
+    CodedBitstreamH264Context *h264 = ctx->priv_data;
+    const H264RawSPS *sps = h264->active_sps;
+    int chroma;
+    int err, i, j;
+
+    ue(luma_log2_weight_denom, 0, 7);
+
+    chroma = !sps->separate_colour_plane_flag && sps->chroma_format_idc != 0;
+    if (chroma)
+        ue(chroma_log2_weight_denom, 0, 7);
+
+    for (i = 0; i <= current->num_ref_idx_l0_active_minus1; i++) {
+        flag(luma_weight_l0_flag[i]);
+        if (current->luma_weight_l0_flag[i]) {
+            se(luma_weight_l0[i], -128, +127);
+            se(luma_offset_l0[i], -128, +127);
+        }
+        if (chroma) {
+            flag(chroma_weight_l0_flag[i]);
+            if (current->chroma_weight_l0_flag[i]) {
+                for (j = 0; j < 2; j++) {
+                    se(chroma_weight_l0[i][j], -128, +127);
+                    se(chroma_offset_l0[i][j], -128, +127);
+                }
+            }
+        }
+    }
+
+    if (current->slice_type % 5 == 1) {
+        for (i = 0; i <= current->num_ref_idx_l1_active_minus1; i++) {
+            flag(luma_weight_l1_flag[i]);
+            if (current->luma_weight_l1_flag[i]) {
+                se(luma_weight_l1[i], -128, +127);
+                se(luma_offset_l1[i], -128, +127);
+            }
+            if (chroma) {
+                flag(chroma_weight_l1_flag[i]);
+                if (current->chroma_weight_l1_flag[i]) {
+                    for (j = 0; j < 2; j++) {
+                        se(chroma_weight_l1[i][j], -128, +127);
+                        se(chroma_offset_l1[i][j], -128, +127);
+                    }
+                }
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int FUNC(dec_ref_pic_marking)(CodedBitstreamContext *ctx, RWContext *rw,
+                                     H264RawSliceHeader *current, int idr_pic_flag)
+{
+    CodedBitstreamH264Context *h264 = ctx->priv_data;
+    const H264RawSPS *sps = h264->active_sps;
+    int err, i;
+    uint32_t mmco;
+
+    if (idr_pic_flag) {
+        flag(no_output_of_prior_pics_flag);
+        flag(long_term_reference_flag);
+    } else {
+        flag(adaptive_ref_pic_marking_mode_flag);
+        if (current->adaptive_ref_pic_marking_mode_flag) {
+            for (i = 0; i < H264_MAX_MMCO_COUNT; i++) {
+                xue(memory_management_control_operation,
+                    current->mmco[i].memory_management_control_operation,
+                    0, 6);
+
+                mmco = current->mmco[i].memory_management_control_operation;
+                if (mmco == 0)
+                    break;
+
+                if (mmco == 1 || mmco == 3)
+                    xue(difference_of_pic_nums_minus1,
+                        current->mmco[i].difference_of_pic_nums_minus1,
+                        0, INT32_MAX);
+                if (mmco == 2)
+                    xue(long_term_pic_num,
+                        current->mmco[i].long_term_pic_num,
+                        0, sps->max_num_ref_frames - 1);
+                if (mmco == 3 || mmco == 6)
+                    xue(long_term_frame_idx,
+                        current->mmco[i].long_term_frame_idx,
+                        0, sps->max_num_ref_frames - 1);
+                if (mmco == 4)
+                    xue(max_long_term_frame_idx_plus1,
+                        current->mmco[i].max_long_term_frame_idx_plus1,
+                        0, sps->max_num_ref_frames);
+            }
+            if (i == H264_MAX_MMCO_COUNT) {
+                av_log(ctx->log_ctx, AV_LOG_ERROR, "Too many "
+                       "memory management control operations.\n");
+                return AVERROR_INVALIDDATA;
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int FUNC(slice_header)(CodedBitstreamContext *ctx, RWContext *rw,
+                              H264RawSliceHeader *current)
+{
+    CodedBitstreamH264Context *h264 = ctx->priv_data;
+    const H264RawSPS *sps;
+    const H264RawPPS *pps;
+    int err;
+    int idr_pic_flag;
+    int slice_type_i, slice_type_p, slice_type_b;
+    int slice_type_si, slice_type_sp;
+
+    HEADER("Slice Header");
+
+    CHECK(FUNC(nal_unit_header)(ctx, rw, &current->nal_unit_header,
+                                1 << H264_NAL_SLICE     |
+                                1 << H264_NAL_IDR_SLICE |
+                                1 << H264_NAL_AUXILIARY_SLICE));
+
+    if (current->nal_unit_header.nal_unit_type == H264_NAL_AUXILIARY_SLICE) {
+        if (!h264->last_slice_nal_unit_type) {
+            av_log(ctx->log_ctx, AV_LOG_ERROR, "Auxiliary slice "
+                   "is not decodable without the main picture "
+                   "in the same access unit.\n");
+            return AVERROR_INVALIDDATA;
+        }
+    } else {
+        h264->last_slice_nal_unit_type =
+            current->nal_unit_header.nal_unit_type;
+    }
+    idr_pic_flag = h264->last_slice_nal_unit_type == H264_NAL_IDR_SLICE;
+
+    ue(first_mb_in_slice, 0, H264_MAX_MB_PIC_SIZE - 1);
+    ue(slice_type, 0, 9);
+
+    slice_type_i  = current->slice_type % 5 == 2;
+    slice_type_p  = current->slice_type % 5 == 0;
+    slice_type_b  = current->slice_type % 5 == 1;
+    slice_type_si = current->slice_type % 5 == 4;
+    slice_type_sp = current->slice_type % 5 == 3;
+
+    if (idr_pic_flag && !(slice_type_i || slice_type_si)) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid slice type %d "
+               "for IDR picture.\n", current->slice_type);
+        return AVERROR_INVALIDDATA;
+    }
+
+    ue(pic_parameter_set_id, 0, 255);
+
+    pps = h264->pps[current->pic_parameter_set_id];
+    if (!pps) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR, "PPS id %d not available.\n",
+               current->pic_parameter_set_id);
+        return AVERROR_INVALIDDATA;
+    }
+    h264->active_pps = pps;
+
+    sps = h264->sps[pps->seq_parameter_set_id];
+    if (!sps) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR, "SPS id %d not available.\n",
+               pps->seq_parameter_set_id);
+        return AVERROR_INVALIDDATA;
+    }
+    h264->active_sps = sps;
+
+    if (sps->separate_colour_plane_flag)
+        u(2, colour_plane_id, 0, 2);
+
+    u(sps->log2_max_frame_num_minus4 + 4, frame_num,
+      0, (1 << (sps->log2_max_frame_num_minus4 + 4)) - 1);
+
+    if (!sps->frame_mbs_only_flag) {
+        flag(field_pic_flag);
+        if (current->field_pic_flag)
+            flag(bottom_field_flag);
+        else
+            infer(bottom_field_flag, 0);
+    } else {
+        infer(field_pic_flag,    0);
+        infer(bottom_field_flag, 0);
+    }
+
+    if (idr_pic_flag)
+        ue(idr_pic_id, 0, 65535);
+
+    if (sps->pic_order_cnt_type == 0) {
+        u(sps->log2_max_pic_order_cnt_lsb_minus4 + 4, pic_order_cnt_lsb,
+          0, (1 << (sps->log2_max_pic_order_cnt_lsb_minus4 + 4)) - 1);
+        if (pps->bottom_field_pic_order_in_frame_present_flag &&
+            !current->field_pic_flag)
+            se(delta_pic_order_cnt_bottom, INT32_MIN + 1, INT32_MAX);
+
+    } else if (sps->pic_order_cnt_type == 1) {
+        if (!sps->delta_pic_order_always_zero_flag) {
+            se(delta_pic_order_cnt[0], INT32_MIN + 1, INT32_MAX);
+            if (pps->bottom_field_pic_order_in_frame_present_flag &&
+                !current->field_pic_flag)
+                se(delta_pic_order_cnt[1], INT32_MIN + 1, INT32_MAX);
+            else
+                infer(delta_pic_order_cnt[1], 0);
+        } else {
+            infer(delta_pic_order_cnt[0], 0);
+            infer(delta_pic_order_cnt[1], 0);
+        }
+    }
+
+    if (pps->redundant_pic_cnt_present_flag)
+        ue(redundant_pic_cnt, 0, 127);
+
+    if (slice_type_b)
+        flag(direct_spatial_mv_pred_flag);
+
+    if (slice_type_p || slice_type_sp || slice_type_b) {
+        flag(num_ref_idx_active_override_flag);
+        if (current->num_ref_idx_active_override_flag) {
+            ue(num_ref_idx_l0_active_minus1, 0, 31);
+            if (slice_type_b)
+                ue(num_ref_idx_l1_active_minus1, 0, 31);
+        } else {
+            infer(num_ref_idx_l0_active_minus1,
+                  pps->num_ref_idx_l0_default_active_minus1);
+            infer(num_ref_idx_l1_active_minus1,
+                  pps->num_ref_idx_l1_default_active_minus1);
+        }
+    }
+
+    if (current->nal_unit_header.nal_unit_type == 20 ||
+        current->nal_unit_header.nal_unit_type == 21) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR, "MVC / 3DAVC not supported.\n");
+        return AVERROR_PATCHWELCOME;
+    } else {
+        CHECK(FUNC(ref_pic_list_modification)(ctx, rw, current));
+    }
+
+    if ((pps->weighted_pred_flag && (slice_type_p || slice_type_sp)) ||
+        (pps->weighted_bipred_idc == 1 && slice_type_b)) {
+        CHECK(FUNC(pred_weight_table)(ctx, rw, current));
+    }
+
+    if (current->nal_unit_header.nal_ref_idc != 0) {
+        CHECK(FUNC(dec_ref_pic_marking)(ctx, rw, current, idr_pic_flag));
+    }
+
+    if (pps->entropy_coding_mode_flag &&
+        !slice_type_i && !slice_type_si) {
+        ue(cabac_init_idc, 0, 2);
+    }
+
+    se(slice_qp_delta, - 51 - 6 * sps->bit_depth_luma_minus8,
+                       + 51 + 6 * sps->bit_depth_luma_minus8);
+    if (slice_type_sp || slice_type_si) {
+        if (slice_type_sp)
+            flag(sp_for_switch_flag);
+        se(slice_qs_delta, -51, +51);
+    }
+
+    if (pps->deblocking_filter_control_present_flag) {
+        ue(disable_deblocking_filter_idc, 0, 2);
+        if (current->disable_deblocking_filter_idc != 1) {
+            se(slice_alpha_c0_offset_div2, -6, +6);
+            se(slice_beta_offset_div2,     -6, +6);
+        } else {
+            infer(slice_alpha_c0_offset_div2, 0);
+            infer(slice_beta_offset_div2,     0);
+        }
+    } else {
+        infer(disable_deblocking_filter_idc, 0);
+        infer(slice_alpha_c0_offset_div2,    0);
+        infer(slice_beta_offset_div2,        0);
+    }
+
+    if (pps->num_slice_groups_minus1 > 0 &&
+        pps->slice_group_map_type >= 3 &&
+        pps->slice_group_map_type <= 5) {
+        unsigned int pic_size, max, bits;
+
+        pic_size = (sps->pic_width_in_mbs_minus1 + 1) *
+                   (sps->pic_height_in_map_units_minus1 + 1);
+        max = (pic_size + pps->slice_group_change_rate_minus1) /
+              (pps->slice_group_change_rate_minus1 + 1);
+        bits = av_log2(2 * max - 1);
+
+        u(bits, slice_group_change_cycle, 0, max);
+    }
+
+    if (pps->entropy_coding_mode_flag) {
+        av_unused int one = 1;
+        while (byte_alignment(rw))
+            xu(1, cabac_alignment_one_bit, one, 1, 1);
+    }
+
+    return 0;
+}