133 lines
4.9 KiB
C
133 lines
4.9 KiB
C
/*
|
|
* Copyright (c) 2018, 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 "av1/common/obu_util.h"
|
|
|
|
#include "aom_dsp/bitreader_buffer.h"
|
|
|
|
static aom_codec_err_t read_obu_size(const uint8_t *data,
|
|
size_t bytes_available,
|
|
size_t *const obu_size,
|
|
size_t *const length_field_size) {
|
|
uint64_t u_obu_size = 0;
|
|
if (aom_uleb_decode(data, bytes_available, &u_obu_size, length_field_size) !=
|
|
0) {
|
|
return AOM_CODEC_CORRUPT_FRAME;
|
|
}
|
|
|
|
if (u_obu_size > UINT32_MAX) return AOM_CODEC_CORRUPT_FRAME;
|
|
*obu_size = (size_t)u_obu_size;
|
|
return AOM_CODEC_OK;
|
|
}
|
|
|
|
// Parses OBU header and stores values in 'header'.
|
|
static aom_codec_err_t read_obu_header(struct aom_read_bit_buffer *rb,
|
|
int is_annexb, ObuHeader *header) {
|
|
if (!rb || !header) return AOM_CODEC_INVALID_PARAM;
|
|
|
|
const ptrdiff_t bit_buffer_byte_length = rb->bit_buffer_end - rb->bit_buffer;
|
|
if (bit_buffer_byte_length < 1) return AOM_CODEC_CORRUPT_FRAME;
|
|
|
|
header->size = 1;
|
|
|
|
if (aom_rb_read_bit(rb) != 0) {
|
|
// Forbidden bit. Must not be set.
|
|
return AOM_CODEC_CORRUPT_FRAME;
|
|
}
|
|
|
|
header->type = (OBU_TYPE)aom_rb_read_literal(rb, 4);
|
|
header->has_extension = aom_rb_read_bit(rb);
|
|
header->has_size_field = aom_rb_read_bit(rb);
|
|
|
|
if (!header->has_size_field && !is_annexb) {
|
|
// section 5 obu streams must have obu_size field set.
|
|
return AOM_CODEC_UNSUP_BITSTREAM;
|
|
}
|
|
|
|
// obu_reserved_1bit must be set to 0. The value is ignored by a decoder.
|
|
aom_rb_read_bit(rb);
|
|
|
|
if (header->has_extension) {
|
|
if (bit_buffer_byte_length == 1) return AOM_CODEC_CORRUPT_FRAME;
|
|
|
|
header->size += 1;
|
|
header->temporal_layer_id = aom_rb_read_literal(rb, 3);
|
|
header->spatial_layer_id = aom_rb_read_literal(rb, 2);
|
|
// extension_header_reserved_3bits must be set to 0. The value is ignored by
|
|
// a decoder.
|
|
aom_rb_read_literal(rb, 3);
|
|
} else {
|
|
header->temporal_layer_id = 0;
|
|
header->spatial_layer_id = 0;
|
|
}
|
|
|
|
return AOM_CODEC_OK;
|
|
}
|
|
|
|
aom_codec_err_t aom_read_obu_header(uint8_t *buffer, size_t buffer_length,
|
|
size_t *consumed, ObuHeader *header,
|
|
int is_annexb) {
|
|
if (buffer_length < 1 || !consumed || !header) return AOM_CODEC_INVALID_PARAM;
|
|
|
|
// TODO(tomfinegan): Set the error handler here and throughout this file, and
|
|
// confirm parsing work done via aom_read_bit_buffer is successful.
|
|
struct aom_read_bit_buffer rb = { buffer, buffer + buffer_length, 0, NULL,
|
|
NULL };
|
|
aom_codec_err_t parse_result = read_obu_header(&rb, is_annexb, header);
|
|
if (parse_result == AOM_CODEC_OK) *consumed = header->size;
|
|
return parse_result;
|
|
}
|
|
|
|
aom_codec_err_t aom_read_obu_header_and_size(const uint8_t *data,
|
|
size_t bytes_available,
|
|
int is_annexb,
|
|
ObuHeader *obu_header,
|
|
size_t *const payload_size,
|
|
size_t *const bytes_read) {
|
|
size_t length_field_size_obu = 0;
|
|
size_t length_field_size_payload = 0;
|
|
size_t obu_size = 0;
|
|
aom_codec_err_t status;
|
|
|
|
if (is_annexb) {
|
|
// Size field comes before the OBU header, and includes the OBU header
|
|
status =
|
|
read_obu_size(data, bytes_available, &obu_size, &length_field_size_obu);
|
|
|
|
if (status != AOM_CODEC_OK) return status;
|
|
}
|
|
|
|
struct aom_read_bit_buffer rb = { data + length_field_size_obu,
|
|
data + bytes_available, 0, NULL, NULL };
|
|
|
|
status = read_obu_header(&rb, is_annexb, obu_header);
|
|
if (status != AOM_CODEC_OK) return status;
|
|
|
|
if (!obu_header->has_size_field) {
|
|
assert(is_annexb);
|
|
// Derive the payload size from the data we've already read
|
|
if (obu_size < obu_header->size) return AOM_CODEC_CORRUPT_FRAME;
|
|
|
|
*payload_size = obu_size - obu_header->size;
|
|
} else {
|
|
// Size field comes after the OBU header, and is just the payload size
|
|
status = read_obu_size(
|
|
data + length_field_size_obu + obu_header->size,
|
|
bytes_available - length_field_size_obu - obu_header->size,
|
|
payload_size, &length_field_size_payload);
|
|
if (status != AOM_CODEC_OK) return status;
|
|
}
|
|
|
|
*bytes_read =
|
|
length_field_size_obu + obu_header->size + length_field_size_payload;
|
|
return AOM_CODEC_OK;
|
|
}
|