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Dactyloidae/third_party/aom/av1/decoder/obu.c

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/*
* Copyright (c) 2017, Alliance for Open Media. All rights reserved
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
#include <assert.h>
#include "config/aom_config.h"
#include "aom/aom_codec.h"
#include "aom_dsp/bitreader_buffer.h"
#include "aom_ports/mem_ops.h"
#include "av1/common/common.h"
#include "av1/common/obu_util.h"
#include "av1/common/timing.h"
#include "av1/decoder/decoder.h"
#include "av1/decoder/decodeframe.h"
#include "av1/decoder/obu.h"
// Picture prediction structures (0-12 are predefined) in scalability metadata.
typedef enum {
SCALABILITY_L1T2 = 0,
SCALABILITY_L1T3 = 1,
SCALABILITY_L2T1 = 2,
SCALABILITY_L2T2 = 3,
SCALABILITY_L2T3 = 4,
SCALABILITY_S2T1 = 5,
SCALABILITY_S2T2 = 6,
SCALABILITY_S2T3 = 7,
SCALABILITY_L2T1h = 8,
SCALABILITY_L2T2h = 9,
SCALABILITY_L2T3h = 10,
SCALABILITY_S2T1h = 11,
SCALABILITY_S2T2h = 12,
SCALABILITY_S2T3h = 13,
SCALABILITY_SS = 14
} SCALABILITY_STRUCTURES;
aom_codec_err_t aom_get_num_layers_from_operating_point_idc(
int operating_point_idc, unsigned int *number_spatial_layers,
unsigned int *number_temporal_layers) {
// derive number of spatial/temporal layers from operating_point_idc
if (!number_spatial_layers || !number_temporal_layers)
return AOM_CODEC_INVALID_PARAM;
if (operating_point_idc == 0) {
*number_temporal_layers = 1;
*number_spatial_layers = 1;
} else {
*number_spatial_layers = 0;
*number_temporal_layers = 0;
for (int j = 0; j < MAX_NUM_SPATIAL_LAYERS; j++) {
*number_spatial_layers +=
(operating_point_idc >> (j + MAX_NUM_TEMPORAL_LAYERS)) & 0x1;
}
for (int j = 0; j < MAX_NUM_TEMPORAL_LAYERS; j++) {
*number_temporal_layers += (operating_point_idc >> j) & 0x1;
}
}
return AOM_CODEC_OK;
}
static int is_obu_in_current_operating_point(AV1Decoder *pbi,
ObuHeader obu_header) {
if (!pbi->current_operating_point) {
return 1;
}
if ((pbi->current_operating_point >> obu_header.temporal_layer_id) & 0x1 &&
(pbi->current_operating_point >> (obu_header.spatial_layer_id + 8)) &
0x1) {
return 1;
}
return 0;
}
static int byte_alignment(AV1_COMMON *const cm,
struct aom_read_bit_buffer *const rb) {
while (rb->bit_offset & 7) {
if (aom_rb_read_bit(rb)) {
cm->error.error_code = AOM_CODEC_CORRUPT_FRAME;
return -1;
}
}
return 0;
}
static uint32_t read_temporal_delimiter_obu() { return 0; }
// Returns a boolean that indicates success.
static int read_bitstream_level(BitstreamLevel *bl,
struct aom_read_bit_buffer *rb) {
const uint8_t seq_level_idx = aom_rb_read_literal(rb, LEVEL_BITS);
if (!is_valid_seq_level_idx(seq_level_idx)) return 0;
bl->major = (seq_level_idx >> LEVEL_MINOR_BITS) + LEVEL_MAJOR_MIN;
bl->minor = seq_level_idx & ((1 << LEVEL_MINOR_BITS) - 1);
return 1;
}
// Returns whether two sequence headers are consistent with each other.
// TODO(huisu,wtc@google.com): make sure the code matches the spec exactly.
static int are_seq_headers_consistent(const SequenceHeader *seq_params_old,
const SequenceHeader *seq_params_new) {
return !memcmp(seq_params_old, seq_params_new, sizeof(SequenceHeader));
}
// On success, sets pbi->sequence_header_ready to 1 and returns the number of
// bytes read from 'rb'.
// On failure, sets pbi->common.error.error_code and returns 0.
static uint32_t read_sequence_header_obu(AV1Decoder *pbi,
struct aom_read_bit_buffer *rb) {
AV1_COMMON *const cm = &pbi->common;
const uint32_t saved_bit_offset = rb->bit_offset;
// Verify rb has been configured to report errors.
assert(rb->error_handler);
// Use a local variable to store the information as we decode. At the end,
// if no errors have occurred, cm->seq_params is updated.
SequenceHeader sh = cm->seq_params;
SequenceHeader *const seq_params = &sh;
seq_params->profile = av1_read_profile(rb);
if (seq_params->profile > CONFIG_MAX_DECODE_PROFILE) {
cm->error.error_code = AOM_CODEC_UNSUP_BITSTREAM;
return 0;
}
// Still picture or not
seq_params->still_picture = aom_rb_read_bit(rb);
seq_params->reduced_still_picture_hdr = aom_rb_read_bit(rb);
// Video must have reduced_still_picture_hdr = 0
if (!seq_params->still_picture && seq_params->reduced_still_picture_hdr) {
cm->error.error_code = AOM_CODEC_UNSUP_BITSTREAM;
return 0;
}
if (seq_params->reduced_still_picture_hdr) {
cm->timing_info_present = 0;
seq_params->decoder_model_info_present_flag = 0;
seq_params->display_model_info_present_flag = 0;
seq_params->operating_points_cnt_minus_1 = 0;
seq_params->operating_point_idc[0] = 0;
if (!read_bitstream_level(&seq_params->level[0], rb)) {
cm->error.error_code = AOM_CODEC_UNSUP_BITSTREAM;
return 0;
}
seq_params->tier[0] = 0;
cm->op_params[0].decoder_model_param_present_flag = 0;
cm->op_params[0].display_model_param_present_flag = 0;
} else {
cm->timing_info_present = aom_rb_read_bit(rb); // timing_info_present_flag
if (cm->timing_info_present) {
av1_read_timing_info_header(cm, rb);
seq_params->decoder_model_info_present_flag = aom_rb_read_bit(rb);
if (seq_params->decoder_model_info_present_flag)
av1_read_decoder_model_info(cm, rb);
} else {
seq_params->decoder_model_info_present_flag = 0;
}
seq_params->display_model_info_present_flag = aom_rb_read_bit(rb);
seq_params->operating_points_cnt_minus_1 =
aom_rb_read_literal(rb, OP_POINTS_CNT_MINUS_1_BITS);
for (int i = 0; i < seq_params->operating_points_cnt_minus_1 + 1; i++) {
seq_params->operating_point_idc[i] =
aom_rb_read_literal(rb, OP_POINTS_IDC_BITS);
if (!read_bitstream_level(&seq_params->level[i], rb)) {
cm->error.error_code = AOM_CODEC_UNSUP_BITSTREAM;
return 0;
}
// This is the seq_level_idx[i] > 7 check in the spec. seq_level_idx 7
// is equivalent to level 3.3.
if (seq_params->level[i].major > 3)
seq_params->tier[i] = aom_rb_read_bit(rb);
else
seq_params->tier[i] = 0;
if (seq_params->decoder_model_info_present_flag) {
cm->op_params[i].decoder_model_param_present_flag = aom_rb_read_bit(rb);
if (cm->op_params[i].decoder_model_param_present_flag)
av1_read_op_parameters_info(cm, rb, i);
} else {
cm->op_params[i].decoder_model_param_present_flag = 0;
}
if (cm->timing_info_present &&
(cm->timing_info.equal_picture_interval ||
cm->op_params[i].decoder_model_param_present_flag)) {
cm->op_params[i].bitrate = max_level_bitrate(
seq_params->profile,
major_minor_to_seq_level_idx(seq_params->level[i]),
seq_params->tier[i]);
// Level with seq_level_idx = 31 returns a high "dummy" bitrate to pass
// the check
if (cm->op_params[i].bitrate == 0)
aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
"AV1 does not support this combination of "
"profile, level, and tier.");
// Buffer size in bits/s is bitrate in bits/s * 1 s
cm->op_params[i].buffer_size = cm->op_params[i].bitrate;
}
if (cm->timing_info_present && cm->timing_info.equal_picture_interval &&
!cm->op_params[i].decoder_model_param_present_flag) {
// When the decoder_model_parameters are not sent for this op, set
// the default ones that can be used with the resource availability mode
cm->op_params[i].decoder_buffer_delay = 70000;
cm->op_params[i].encoder_buffer_delay = 20000;
cm->op_params[i].low_delay_mode_flag = 0;
}
if (seq_params->display_model_info_present_flag) {
cm->op_params[i].display_model_param_present_flag = aom_rb_read_bit(rb);
if (cm->op_params[i].display_model_param_present_flag) {
cm->op_params[i].initial_display_delay =
aom_rb_read_literal(rb, 4) + 1;
if (cm->op_params[i].initial_display_delay > 10)
aom_internal_error(
&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
"AV1 does not support more than 10 decoded frames delay");
} else {
cm->op_params[i].initial_display_delay = 10;
}
} else {
cm->op_params[i].display_model_param_present_flag = 0;
cm->op_params[i].initial_display_delay = 10;
}
}
}
// This decoder supports all levels. Choose operating point provided by
// external means
int operating_point = pbi->operating_point;
if (operating_point < 0 ||
operating_point > seq_params->operating_points_cnt_minus_1)
operating_point = 0;
pbi->current_operating_point =
seq_params->operating_point_idc[operating_point];
if (aom_get_num_layers_from_operating_point_idc(
pbi->current_operating_point, &cm->number_spatial_layers,
&cm->number_temporal_layers) != AOM_CODEC_OK) {
cm->error.error_code = AOM_CODEC_ERROR;
return 0;
}
av1_read_sequence_header(cm, rb, seq_params);
av1_read_color_config(rb, pbi->allow_lowbitdepth, seq_params, &cm->error);
if (!(seq_params->subsampling_x == 0 && seq_params->subsampling_y == 0) &&
!(seq_params->subsampling_x == 1 && seq_params->subsampling_y == 1) &&
!(seq_params->subsampling_x == 1 && seq_params->subsampling_y == 0)) {
aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
"Only 4:4:4, 4:2:2 and 4:2:0 are currently supported, "
"%d %d subsampling is not supported.\n",
seq_params->subsampling_x, seq_params->subsampling_y);
}
seq_params->film_grain_params_present = aom_rb_read_bit(rb);
if (av1_check_trailing_bits(pbi, rb) != 0) {
// cm->error.error_code is already set.
return 0;
}
// If a sequence header has been decoded before, we check if the new
// one is consistent with the old one.
if (pbi->sequence_header_ready) {
if (!are_seq_headers_consistent(&cm->seq_params, seq_params))
pbi->sequence_header_changed = 1;
}
cm->seq_params = *seq_params;
pbi->sequence_header_ready = 1;
return ((rb->bit_offset - saved_bit_offset + 7) >> 3);
}
// On success, returns the frame header size. On failure, calls
// aom_internal_error and does not return.
static uint32_t read_frame_header_obu(AV1Decoder *pbi,
struct aom_read_bit_buffer *rb,
const uint8_t *data,
const uint8_t **p_data_end,
int trailing_bits_present) {
return av1_decode_frame_headers_and_setup(pbi, rb, data, p_data_end,
trailing_bits_present);
}
static int32_t read_tile_group_header(AV1Decoder *pbi,
struct aom_read_bit_buffer *rb,
int *start_tile, int *end_tile,
int tile_start_implicit) {
AV1_COMMON *const cm = &pbi->common;
uint32_t saved_bit_offset = rb->bit_offset;
int tile_start_and_end_present_flag = 0;
const int num_tiles = pbi->common.tile_rows * pbi->common.tile_cols;
if (!pbi->common.large_scale_tile && num_tiles > 1) {
tile_start_and_end_present_flag = aom_rb_read_bit(rb);
}
if (pbi->common.large_scale_tile || num_tiles == 1 ||
!tile_start_and_end_present_flag) {
*start_tile = 0;
*end_tile = num_tiles - 1;
return ((rb->bit_offset - saved_bit_offset + 7) >> 3);
}
if (tile_start_implicit && tile_start_and_end_present_flag) {
aom_internal_error(
&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
"For OBU_FRAME type obu tile_start_and_end_present_flag must be 0");
return -1;
}
*start_tile =
aom_rb_read_literal(rb, cm->log2_tile_rows + cm->log2_tile_cols);
*end_tile = aom_rb_read_literal(rb, cm->log2_tile_rows + cm->log2_tile_cols);
return ((rb->bit_offset - saved_bit_offset + 7) >> 3);
}
static uint32_t read_one_tile_group_obu(
AV1Decoder *pbi, struct aom_read_bit_buffer *rb, int is_first_tg,
const uint8_t *data, const uint8_t *data_end, const uint8_t **p_data_end,
int *is_last_tg, int tile_start_implicit) {
AV1_COMMON *const cm = &pbi->common;
int start_tile, end_tile;
int32_t header_size, tg_payload_size;
assert((rb->bit_offset & 7) == 0);
assert(rb->bit_buffer + aom_rb_bytes_read(rb) == data);
header_size = read_tile_group_header(pbi, rb, &start_tile, &end_tile,
tile_start_implicit);
if (header_size == -1 || byte_alignment(cm, rb)) return 0;
if (start_tile > end_tile) return header_size;
data += header_size;
av1_decode_tg_tiles_and_wrapup(pbi, data, data_end, p_data_end, start_tile,
end_tile, is_first_tg);
tg_payload_size = (uint32_t)(*p_data_end - data);
// TODO(shan): For now, assume all tile groups received in order
*is_last_tg = end_tile == cm->tile_rows * cm->tile_cols - 1;
return header_size + tg_payload_size;
}
static void alloc_tile_list_buffer(AV1Decoder *pbi) {
// TODO(yunqing): for now, copy each tile's decoded YUV data directly to the
// output buffer. This needs to be modified according to the application
// requirement.
AV1_COMMON *const cm = &pbi->common;
const int tile_width_in_pixels = cm->tile_width * MI_SIZE;
const int tile_height_in_pixels = cm->tile_height * MI_SIZE;
const int ssy = cm->seq_params.subsampling_y;
const int ssx = cm->seq_params.subsampling_x;
const int num_planes = av1_num_planes(cm);
const size_t yplane_tile_size = tile_height_in_pixels * tile_width_in_pixels;
const size_t uvplane_tile_size =
(num_planes > 1)
? (tile_height_in_pixels >> ssy) * (tile_width_in_pixels >> ssx)
: 0;
const size_t tile_size = (cm->seq_params.use_highbitdepth ? 2 : 1) *
(yplane_tile_size + 2 * uvplane_tile_size);
pbi->tile_list_size = tile_size * (pbi->tile_count_minus_1 + 1);
if (pbi->tile_list_size > pbi->buffer_sz) {
if (pbi->tile_list_output != NULL) aom_free(pbi->tile_list_output);
pbi->tile_list_output = NULL;
pbi->tile_list_output = (uint8_t *)aom_memalign(32, pbi->tile_list_size);
if (pbi->tile_list_output == NULL)
aom_internal_error(&cm->error, AOM_CODEC_MEM_ERROR,
"Failed to allocate the tile list output buffer");
pbi->buffer_sz = pbi->tile_list_size;
}
}
static void copy_decoded_tile_to_tile_list_buffer(AV1Decoder *pbi,
uint8_t **output) {
AV1_COMMON *const cm = &pbi->common;
const int tile_width_in_pixels = cm->tile_width * MI_SIZE;
const int tile_height_in_pixels = cm->tile_height * MI_SIZE;
const int ssy = cm->seq_params.subsampling_y;
const int ssx = cm->seq_params.subsampling_x;
const int num_planes = av1_num_planes(cm);
// Copy decoded tile to the tile list output buffer.
YV12_BUFFER_CONFIG *cur_frame = get_frame_new_buffer(cm);
const int mi_row = pbi->dec_tile_row * cm->tile_height;
const int mi_col = pbi->dec_tile_col * cm->tile_width;
const int is_hbd = (cur_frame->flags & YV12_FLAG_HIGHBITDEPTH) ? 1 : 0;
uint8_t *bufs[MAX_MB_PLANE] = { NULL, NULL, NULL };
int strides[MAX_MB_PLANE] = { 0, 0, 0 };
int plane;
for (plane = 0; plane < num_planes; ++plane) {
int shift_x = plane > 0 ? ssx : 0;
int shift_y = plane > 0 ? ssy : 0;
bufs[plane] = cur_frame->buffers[plane];
strides[plane] =
(plane > 0) ? cur_frame->strides[1] : cur_frame->strides[0];
bufs[plane] += mi_row * (MI_SIZE >> shift_y) * strides[plane] +
mi_col * (MI_SIZE >> shift_x);
if (is_hbd) {
bufs[plane] = (uint8_t *)CONVERT_TO_SHORTPTR(bufs[plane]);
strides[plane] *= 2;
}
int w, h;
w = (plane > 0 && shift_x > 0) ? ((tile_width_in_pixels + 1) >> shift_x)
: tile_width_in_pixels;
w *= (1 + is_hbd);
h = (plane > 0 && shift_y > 0) ? ((tile_height_in_pixels + 1) >> shift_y)
: tile_height_in_pixels;
int j;
for (j = 0; j < h; ++j) {
memcpy(*output, bufs[plane], w);
bufs[plane] += strides[plane];
*output += w;
}
}
}
// Only called while large_scale_tile = 1.
static uint32_t read_and_decode_one_tile_list(AV1Decoder *pbi,
struct aom_read_bit_buffer *rb,
const uint8_t *data,
const uint8_t *data_end,
const uint8_t **p_data_end,
int *frame_decoding_finished) {
AV1_COMMON *const cm = &pbi->common;
uint32_t tile_list_payload_size = 0;
const int num_tiles = cm->tile_cols * cm->tile_rows;
const int start_tile = 0;
const int end_tile = num_tiles - 1;
int i = 0;
// Process the tile list info.
pbi->output_frame_width_in_tiles_minus_1 = aom_rb_read_literal(rb, 8);
pbi->output_frame_height_in_tiles_minus_1 = aom_rb_read_literal(rb, 8);
pbi->tile_count_minus_1 = aom_rb_read_literal(rb, 16);
if (pbi->tile_count_minus_1 > MAX_TILES - 1) {
cm->error.error_code = AOM_CODEC_CORRUPT_FRAME;
return 0;
}
// Allocate output frame buffer for the tile list.
alloc_tile_list_buffer(pbi);
uint32_t tile_list_info_bytes = 4;
tile_list_payload_size += tile_list_info_bytes;
data += tile_list_info_bytes;
uint8_t *output = pbi->tile_list_output;
for (i = 0; i <= pbi->tile_count_minus_1; i++) {
// Process 1 tile.
// Reset the bit reader.
rb->bit_offset = 0;
rb->bit_buffer = data;
// Read out the tile info.
uint32_t tile_info_bytes = 5;
// Set reference for each tile.
int ref_idx = aom_rb_read_literal(rb, 8);
if (ref_idx >= MAX_EXTERNAL_REFERENCES) {
cm->error.error_code = AOM_CODEC_CORRUPT_FRAME;
return 0;
}
av1_set_reference_dec(cm, 0, 1, &pbi->ext_refs.refs[ref_idx]);
pbi->dec_tile_row = aom_rb_read_literal(rb, 8);
pbi->dec_tile_col = aom_rb_read_literal(rb, 8);
if (pbi->dec_tile_row < 0 || pbi->dec_tile_col < 0 ||
pbi->dec_tile_row >= cm->tile_rows ||
pbi->dec_tile_col >= cm->tile_cols) {
cm->error.error_code = AOM_CODEC_CORRUPT_FRAME;
return 0;
}
pbi->coded_tile_data_size = aom_rb_read_literal(rb, 16) + 1;
data += tile_info_bytes;
if ((size_t)(data_end - data) < pbi->coded_tile_data_size) {
cm->error.error_code = AOM_CODEC_CORRUPT_FRAME;
return 0;
}
av1_decode_tg_tiles_and_wrapup(pbi, data, data + pbi->coded_tile_data_size,
p_data_end, start_tile, end_tile, 0);
uint32_t tile_payload_size = (uint32_t)(*p_data_end - data);
tile_list_payload_size += tile_info_bytes + tile_payload_size;
// Update data ptr for next tile decoding.
data = *p_data_end;
assert(data <= data_end);
// Copy the decoded tile to the tile list output buffer.
copy_decoded_tile_to_tile_list_buffer(pbi, &output);
}
*frame_decoding_finished = 1;
return tile_list_payload_size;
}
static void read_metadata_itut_t35(const uint8_t *data, size_t sz) {
struct aom_read_bit_buffer rb = { data, data + sz, 0, NULL, NULL };
for (size_t i = 0; i < sz; i++) {
aom_rb_read_literal(&rb, 8);
}
}
static void read_metadata_hdr_cll(const uint8_t *data, size_t sz) {
struct aom_read_bit_buffer rb = { data, data + sz, 0, NULL, NULL };
aom_rb_read_literal(&rb, 16); // max_cll
aom_rb_read_literal(&rb, 16); // max_fall
}
static void read_metadata_hdr_mdcv(const uint8_t *data, size_t sz) {
struct aom_read_bit_buffer rb = { data, data + sz, 0, NULL, NULL };
for (int i = 0; i < 3; i++) {
aom_rb_read_literal(&rb, 16); // primary_i_chromaticity_x
aom_rb_read_literal(&rb, 16); // primary_i_chromaticity_y
}
aom_rb_read_literal(&rb, 16); // white_point_chromaticity_x
aom_rb_read_literal(&rb, 16); // white_point_chromaticity_y
aom_rb_read_unsigned_literal(&rb, 32); // luminance_max
aom_rb_read_unsigned_literal(&rb, 32); // luminance_min
}
static void scalability_structure(struct aom_read_bit_buffer *rb) {
int spatial_layers_cnt = aom_rb_read_literal(rb, 2);
int spatial_layer_dimensions_present_flag = aom_rb_read_bit(rb);
int spatial_layer_description_present_flag = aom_rb_read_bit(rb);
int temporal_group_description_present_flag = aom_rb_read_bit(rb);
aom_rb_read_literal(rb, 3); // reserved
if (spatial_layer_dimensions_present_flag) {
int i;
for (i = 0; i < spatial_layers_cnt + 1; i++) {
aom_rb_read_literal(rb, 16);
aom_rb_read_literal(rb, 16);
}
}
if (spatial_layer_description_present_flag) {
int i;
for (i = 0; i < spatial_layers_cnt + 1; i++) {
aom_rb_read_literal(rb, 8);
}
}
if (temporal_group_description_present_flag) {
int i, j, temporal_group_size;
temporal_group_size = aom_rb_read_literal(rb, 8);
for (i = 0; i < temporal_group_size; i++) {
aom_rb_read_literal(rb, 3);
aom_rb_read_bit(rb);
aom_rb_read_bit(rb);
int temporal_group_ref_cnt = aom_rb_read_literal(rb, 3);
for (j = 0; j < temporal_group_ref_cnt; j++) {
aom_rb_read_literal(rb, 8);
}
}
}
}
static void read_metadata_scalability(const uint8_t *data, size_t sz) {
struct aom_read_bit_buffer rb = { data, data + sz, 0, NULL, NULL };
int scalability_mode_idc = aom_rb_read_literal(&rb, 8);
if (scalability_mode_idc == SCALABILITY_SS) {
scalability_structure(&rb);
}
}
static void read_metadata_timecode(const uint8_t *data, size_t sz) {
struct aom_read_bit_buffer rb = { data, data + sz, 0, NULL, NULL };
aom_rb_read_literal(&rb, 5); // counting_type f(5)
int full_timestamp_flag = aom_rb_read_bit(&rb); // full_timestamp_flag f(1)
aom_rb_read_bit(&rb); // discontinuity_flag (f1)
aom_rb_read_bit(&rb); // cnt_dropped_flag f(1)
aom_rb_read_literal(&rb, 9); // n_frames f(9)
if (full_timestamp_flag) {
aom_rb_read_literal(&rb, 6); // seconds_value f(6)
aom_rb_read_literal(&rb, 6); // minutes_value f(6)
aom_rb_read_literal(&rb, 5); // hours_value f(5)
} else {
int seconds_flag = aom_rb_read_bit(&rb); // seconds_flag f(1)
if (seconds_flag) {
aom_rb_read_literal(&rb, 6); // seconds_value f(6)
int minutes_flag = aom_rb_read_bit(&rb); // minutes_flag f(1)
if (minutes_flag) {
aom_rb_read_literal(&rb, 6); // minutes_value f(6)
int hours_flag = aom_rb_read_bit(&rb); // hours_flag f(1)
if (hours_flag) {
aom_rb_read_literal(&rb, 5); // hours_value f(5)
}
}
}
}
// time_offset_length f(5)
int time_offset_length = aom_rb_read_literal(&rb, 5);
if (time_offset_length) {
aom_rb_read_literal(&rb, time_offset_length); // f(time_offset_length)
}
}
static size_t read_metadata(const uint8_t *data, size_t sz) {
size_t type_length;
uint64_t type_value;
OBU_METADATA_TYPE metadata_type;
if (aom_uleb_decode(data, sz, &type_value, &type_length) < 0) {
return sz;
}
metadata_type = (OBU_METADATA_TYPE)type_value;
if (metadata_type == OBU_METADATA_TYPE_ITUT_T35) {
read_metadata_itut_t35(data + type_length, sz - type_length);
} else if (metadata_type == OBU_METADATA_TYPE_HDR_CLL) {
read_metadata_hdr_cll(data + type_length, sz - type_length);
} else if (metadata_type == OBU_METADATA_TYPE_HDR_MDCV) {
read_metadata_hdr_mdcv(data + type_length, sz - type_length);
} else if (metadata_type == OBU_METADATA_TYPE_SCALABILITY) {
read_metadata_scalability(data + type_length, sz - type_length);
} else if (metadata_type == OBU_METADATA_TYPE_TIMECODE) {
read_metadata_timecode(data + type_length, sz - type_length);
}
return sz;
}
// On success, returns a boolean that indicates whether the decoding of the
// current frame is finished. On failure, sets cm->error.error_code and
// returns -1.
int aom_decode_frame_from_obus(struct AV1Decoder *pbi, const uint8_t *data,
const uint8_t *data_end,
const uint8_t **p_data_end) {
AV1_COMMON *const cm = &pbi->common;
int frame_decoding_finished = 0;
int is_first_tg_obu_received = 1;
uint32_t frame_header_size = 0;
ObuHeader obu_header;
memset(&obu_header, 0, sizeof(obu_header));
pbi->seen_frame_header = 0;
if (data_end < data) {
cm->error.error_code = AOM_CODEC_CORRUPT_FRAME;
return -1;
}
// Reset pbi->camera_frame_header_ready to 0 if cm->large_scale_tile = 0.
if (!cm->large_scale_tile) pbi->camera_frame_header_ready = 0;
// decode frame as a series of OBUs
while (!frame_decoding_finished && !cm->error.error_code) {
struct aom_read_bit_buffer rb;
size_t payload_size = 0;
size_t decoded_payload_size = 0;
size_t obu_payload_offset = 0;
size_t bytes_read = 0;
const size_t bytes_available = data_end - data;
if (bytes_available == 0 && !pbi->seen_frame_header) {
*p_data_end = data;
cm->error.error_code = AOM_CODEC_OK;
break;
}
aom_codec_err_t status =
aom_read_obu_header_and_size(data, bytes_available, cm->is_annexb,
&obu_header, &payload_size, &bytes_read);
if (status != AOM_CODEC_OK) {
cm->error.error_code = status;
return -1;
}
// Record obu size header information.
pbi->obu_size_hdr.data = data + obu_header.size;
pbi->obu_size_hdr.size = bytes_read - obu_header.size;
// Note: aom_read_obu_header_and_size() takes care of checking that this
// doesn't cause 'data' to advance past 'data_end'.
data += bytes_read;
if ((size_t)(data_end - data) < payload_size) {
cm->error.error_code = AOM_CODEC_CORRUPT_FRAME;
return -1;
}
cm->temporal_layer_id = obu_header.temporal_layer_id;
cm->spatial_layer_id = obu_header.spatial_layer_id;
if (obu_header.type != OBU_TEMPORAL_DELIMITER &&
obu_header.type != OBU_SEQUENCE_HEADER &&
obu_header.type != OBU_PADDING) {
// don't decode obu if it's not in current operating mode
if (!is_obu_in_current_operating_point(pbi, obu_header)) {
data += payload_size;
continue;
}
}
av1_init_read_bit_buffer(pbi, &rb, data, data + payload_size);
switch (obu_header.type) {
case OBU_TEMPORAL_DELIMITER:
decoded_payload_size = read_temporal_delimiter_obu();
pbi->seen_frame_header = 0;
break;
case OBU_SEQUENCE_HEADER:
decoded_payload_size = read_sequence_header_obu(pbi, &rb);
if (cm->error.error_code != AOM_CODEC_OK) return -1;
break;
case OBU_FRAME_HEADER:
case OBU_REDUNDANT_FRAME_HEADER:
case OBU_FRAME:
// Only decode first frame header received
if (!pbi->seen_frame_header ||
(cm->large_scale_tile && !pbi->camera_frame_header_ready)) {
frame_header_size = read_frame_header_obu(
pbi, &rb, data, p_data_end, obu_header.type != OBU_FRAME);
pbi->seen_frame_header = 1;
if (!pbi->ext_tile_debug && cm->large_scale_tile)
pbi->camera_frame_header_ready = 1;
} else {
// TODO(wtc): Verify that the frame_header_obu is identical to the
// original frame_header_obu. For now just skip frame_header_size
// bytes in the bit buffer.
if (frame_header_size > payload_size) {
cm->error.error_code = AOM_CODEC_CORRUPT_FRAME;
return -1;
}
assert(rb.bit_offset == 0);
rb.bit_offset = 8 * frame_header_size;
}
decoded_payload_size = frame_header_size;
pbi->frame_header_size = frame_header_size;
if (cm->show_existing_frame) {
if (obu_header.type == OBU_FRAME) {
cm->error.error_code = AOM_CODEC_UNSUP_BITSTREAM;
return -1;
}
frame_decoding_finished = 1;
pbi->seen_frame_header = 0;
break;
}
// In large scale tile coding, decode the common camera frame header
// before any tile list OBU.
if (!pbi->ext_tile_debug && pbi->camera_frame_header_ready) {
frame_decoding_finished = 1;
// Skip the rest of the frame data.
decoded_payload_size = payload_size;
// Update data_end.
*p_data_end = data_end;
break;
}
if (obu_header.type != OBU_FRAME) break;
obu_payload_offset = frame_header_size;
// Byte align the reader before reading the tile group.
if (byte_alignment(cm, &rb)) return -1;
AOM_FALLTHROUGH_INTENDED; // fall through to read tile group.
case OBU_TILE_GROUP:
if (!pbi->seen_frame_header) {
cm->error.error_code = AOM_CODEC_CORRUPT_FRAME;
return -1;
}
if (obu_payload_offset > payload_size) {
cm->error.error_code = AOM_CODEC_CORRUPT_FRAME;
return -1;
}
decoded_payload_size += read_one_tile_group_obu(
pbi, &rb, is_first_tg_obu_received, data + obu_payload_offset,
data + payload_size, p_data_end, &frame_decoding_finished,
obu_header.type == OBU_FRAME);
is_first_tg_obu_received = 0;
if (frame_decoding_finished) pbi->seen_frame_header = 0;
break;
case OBU_METADATA:
decoded_payload_size = read_metadata(data, payload_size);
break;
case OBU_TILE_LIST:
if (CONFIG_NORMAL_TILE_MODE) {
cm->error.error_code = AOM_CODEC_UNSUP_BITSTREAM;
return -1;
}
// This OBU type is purely for the large scale tile coding mode.
// The common camera frame header has to be already decoded.
if (!pbi->camera_frame_header_ready) {
cm->error.error_code = AOM_CODEC_CORRUPT_FRAME;
return -1;
}
cm->large_scale_tile = 1;
av1_set_single_tile_decoding_mode(cm);
decoded_payload_size =
read_and_decode_one_tile_list(pbi, &rb, data, data + payload_size,
p_data_end, &frame_decoding_finished);
if (cm->error.error_code != AOM_CODEC_OK) return -1;
break;
case OBU_PADDING:
default:
// Skip unrecognized OBUs
decoded_payload_size = payload_size;
break;
}
// Check that the signalled OBU size matches the actual amount of data read
if (decoded_payload_size > payload_size) {
cm->error.error_code = AOM_CODEC_CORRUPT_FRAME;
return -1;
}
// If there are extra padding bytes, they should all be zero
while (decoded_payload_size < payload_size) {
uint8_t padding_byte = data[decoded_payload_size++];
if (padding_byte != 0) {
cm->error.error_code = AOM_CODEC_CORRUPT_FRAME;
return -1;
}
}
data += payload_size;
}
return frame_decoding_finished;
}
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