static void parse_superframe_index(const uint8_t *data, size_t data_sz,
uint32_t sizes[8], int *count,
vpx_decrypt_cb decrypt_cb,
void *decrypt_state) {
uint8_t marker;
assert(data_sz);
marker = read_marker(decrypt_cb, decrypt_state, data + data_sz - 1);
*count = 0;
if ((marker & 0xe0) == 0xc0) {
const uint32_t frames = (marker & 0x7) + 1;
const uint32_t mag = ((marker >> 3) & 0x3) + 1;
const size_t index_sz = 2 + mag * frames;
uint8_t marker2 = read_marker(decrypt_cb, decrypt_state,
data + data_sz - index_sz);
if (data_sz >= index_sz && marker2 == marker) {
// found a valid superframe index
uint32_t i, j;
const uint8_t *x = &data[data_sz - index_sz + 1];
// frames has a maximum of 8 and mag has a maximum of 4.
uint8_t clear_buffer[32];
assert(sizeof(clear_buffer) >= frames * mag);
if (decrypt_cb) {
decrypt_cb(decrypt_state, x, clear_buffer, frames * mag);
x = clear_buffer;
}
for (i = 0; i < frames; i++) {
uint32_t this_sz = 0;
for (j = 0; j < mag; j++)
this_sz |= (*x++) << (j * 8);
sizes[i] = this_sz;
}
*count = frames;
}
}
}
static vpx_codec_err_t decode_one_iter(vpx_codec_alg_priv_t *ctx,
const uint8_t **data_start_ptr,
const uint8_t *data_end,
uint32_t frame_size, void *user_priv,
long deadline) {
const vpx_codec_err_t res = decode_one(ctx, data_start_ptr, frame_size,
user_priv, deadline);
if (res != VPX_CODEC_OK)
return res;
// Account for suboptimal termination by the encoder.
while (*data_start_ptr < data_end) {
const uint8_t marker = read_marker(ctx->decrypt_cb, ctx->decrypt_state,
*data_start_ptr);
if (marker)
break;
(*data_start_ptr)++;
}
return VPX_CODEC_OK;
}
static vpx_codec_err_t decoder_decode(vpx_codec_alg_priv_t *ctx,
const uint8_t *data, unsigned int data_sz,
void *user_priv, long deadline) {
const uint8_t *data_start = data;
const uint8_t * const data_end = data + data_sz;
vpx_codec_err_t res;
uint32_t frame_sizes[8];
int frame_count;
if (data == NULL && data_sz == 0) {
ctx->flushed = 1;
return VPX_CODEC_OK;
}
// Reset flushed when receiving a valid frame.
ctx->flushed = 0;
// Initialize the decoder workers on the first frame.
if (ctx->frame_workers == NULL) {
const vpx_codec_err_t res = init_decoder(ctx);
if (res != VPX_CODEC_OK)
return res;
}
res = vp9_parse_superframe_index(data, data_sz, frame_sizes, &frame_count,
ctx->decrypt_cb, ctx->decrypt_state);
if (res != VPX_CODEC_OK)
return res;
if (ctx->frame_parallel_decode) {
// Decode in frame parallel mode. When decoding in this mode, the frame
// passed to the decoder must be either a normal frame or a superframe with
// superframe index so the decoder could get each frame's start position
// in the superframe.
if (frame_count > 0) {
int i;
for (i = 0; i < frame_count; ++i) {
const uint8_t *data_start_copy = data_start;
const uint32_t frame_size = frame_sizes[i];
if (data_start < data
|| frame_size > (uint32_t) (data_end - data_start)) {
set_error_detail(ctx, "Invalid frame size in index");
return VPX_CODEC_CORRUPT_FRAME;
}
if (ctx->available_threads == 0) {
// No more threads for decoding. Wait until the next output worker
// finishes decoding. Then copy the decoded frame into cache.
if (ctx->num_cache_frames < FRAME_CACHE_SIZE) {
wait_worker_and_cache_frame(ctx);
} else {
// TODO(hkuang): Add unit test to test this path.
set_error_detail(ctx, "Frame output cache is full.");
return VPX_CODEC_ERROR;
}
}
res = decode_one(ctx, &data_start_copy, frame_size, user_priv,
deadline);
if (res != VPX_CODEC_OK)
return res;
data_start += frame_size;
}
} else {
if (ctx->available_threads == 0) {
// No more threads for decoding. Wait until the next output worker
// finishes decoding. Then copy the decoded frame into cache.
if (ctx->num_cache_frames < FRAME_CACHE_SIZE) {
wait_worker_and_cache_frame(ctx);
} else {
// TODO(hkuang): Add unit test to test this path.
set_error_detail(ctx, "Frame output cache is full.");
return VPX_CODEC_ERROR;
}
}
res = decode_one(ctx, &data, data_sz, user_priv, deadline);
if (res != VPX_CODEC_OK)
return res;
}
} else {
// Decode in serial mode.
if (frame_count > 0) {
int i;
for (i = 0; i < frame_count; ++i) {
const uint8_t *data_start_copy = data_start;
const uint32_t frame_size = frame_sizes[i];
vpx_codec_err_t res;
if (data_start < data
|| frame_size > (uint32_t) (data_end - data_start)) {
set_error_detail(ctx, "Invalid frame size in index");
return VPX_CODEC_CORRUPT_FRAME;
}
res = decode_one(ctx, &data_start_copy, frame_size, user_priv,
deadline);
if (res != VPX_CODEC_OK)
return res;
data_start += frame_size;
}
} else {
while (data_start < data_end) {
const uint32_t frame_size = (uint32_t) (data_end - data_start);
const vpx_codec_err_t res = decode_one(ctx, &data_start, frame_size,
user_priv, deadline);
if (res != VPX_CODEC_OK)
return res;
// Account for suboptimal termination by the encoder.
while (data_start < data_end) {
const uint8_t marker = read_marker(ctx->decrypt_cb,
ctx->decrypt_state, data_start);
if (marker)
break;
++data_start;
}
}
}
}
return res;
}
vpx_codec_err_t vp9_parse_superframe_index(const uint8_t *data,
size_t data_sz,
uint32_t sizes[8], int *count,
vpx_decrypt_cb decrypt_cb,
void *decrypt_state) {
// A chunk ending with a byte matching 0xc0 is an invalid chunk unless
// it is a super frame index. If the last byte of real video compression
// data is 0xc0 the encoder must add a 0 byte. If we have the marker but
// not the associated matching marker byte at the front of the index we have
// an invalid bitstream and need to return an error.
uint8_t marker;
assert(data_sz);
marker = read_marker(decrypt_cb, decrypt_state, data + data_sz - 1);
*count = 0;
if ((marker & 0xe0) == 0xc0) {
const uint32_t frames = (marker & 0x7) + 1;
const uint32_t mag = ((marker >> 3) & 0x3) + 1;
const size_t index_sz = 2 + mag * frames;
// This chunk is marked as having a superframe index but doesn't have
// enough data for it, thus it's an invalid superframe index.
if (data_sz < index_sz)
return VPX_CODEC_CORRUPT_FRAME;
{
const uint8_t marker2 = read_marker(decrypt_cb, decrypt_state,
data + data_sz - index_sz);
// This chunk is marked as having a superframe index but doesn't have
// the matching marker byte at the front of the index therefore it's an
// invalid chunk.
if (marker != marker2)
return VPX_CODEC_CORRUPT_FRAME;
}
{
// Found a valid superframe index.
uint32_t i, j;
const uint8_t *x = &data[data_sz - index_sz + 1];
// Frames has a maximum of 8 and mag has a maximum of 4.
uint8_t clear_buffer[32];
assert(sizeof(clear_buffer) >= frames * mag);
if (decrypt_cb) {
decrypt_cb(decrypt_state, x, clear_buffer, frames * mag);
x = clear_buffer;
}
for (i = 0; i < frames; ++i) {
uint32_t this_sz = 0;
for (j = 0; j < mag; ++j)
this_sz |= (*x++) << (j * 8);
sizes[i] = this_sz;
}
*count = frames;
}
}
return VPX_CODEC_OK;
}