static vpx_codec_err_t vp9_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 *data_end = data + data_sz;
vpx_codec_err_t res = 0;
uint32_t sizes[8];
int frames_this_pts, frame_count = 0;
parse_superframe_index(data, data_sz, sizes, &frames_this_pts);
do {
// Skip over the superframe index, if present
if (data_sz && (*data_start & 0xe0) == 0xc0) {
const uint8_t marker = *data_start;
const uint32_t frames = (marker & 0x7) + 1;
const uint32_t mag = ((marker >> 3) & 0x3) + 1;
const uint32_t index_sz = 2 + mag * frames;
if (data_sz >= index_sz && data_start[index_sz - 1] == marker) {
data_start += index_sz;
data_sz -= index_sz;
if (data_start < data_end)
continue;
else
break;
}
}
// Use the correct size for this frame, if an index is present.
if (frames_this_pts) {
uint32_t this_sz = sizes[frame_count];
if (data_sz < this_sz) {
ctx->base.err_detail = "Invalid frame size in index";
return VPX_CODEC_CORRUPT_FRAME;
}
data_sz = this_sz;
frame_count++;
}
res = decode_one(ctx, &data_start, data_sz, user_priv, deadline);
assert(data_start >= data);
assert(data_start <= data_end);
/* Early exit if there was a decode error */
if (res)
break;
/* Account for suboptimal termination by the encoder. */
while (data_start < data_end && *data_start == 0)
data_start++;
data_sz = data_end - data_start;
} while (data_start < data_end);
return res;
}
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)
return VPX_CODEC_INVALID_PARAM;
parse_superframe_index(data, data_sz, frame_sizes, &frame_count,
ctx->decrypt_cb, ctx->decrypt_state);
if (frame_count > 0) {
int i;
for (i = 0; i < frame_count; ++i) {
const uint32_t frame_size = frame_sizes[i];
if (data_start < data ||
frame_size > (uint32_t)(data_end - data_start)) {
ctx->base.err_detail = "Invalid frame size in index";
return VPX_CODEC_CORRUPT_FRAME;
}
res = decode_one_iter(ctx, &data_start, data_end, frame_size,
user_priv, deadline);
if (res != VPX_CODEC_OK)
return res;
}
} else {
while (data_start < data_end) {
res = decode_one_iter(ctx, &data_start, data_end,
(uint32_t)(data_end - data_start),
user_priv, deadline);
if (res != VPX_CODEC_OK)
return res;
}
}
return VPX_CODEC_OK;
}