return VPX_CODEC_OK;
}
-static INLINE uint8_t read_marker(vpx_decrypt_cb decrypt_cb,
- void *decrypt_state,
- const uint8_t *data) {
- if (decrypt_cb) {
- uint8_t marker;
- decrypt_cb(decrypt_state, data, &marker, 1);
- return marker;
- }
- return *data;
-}
-
-static vpx_codec_err_t 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;
-}
-
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) {
// Reset flushed when receiving a valid frame.
ctx->flushed = 0;
- res = parse_superframe_index(data, data_sz, frame_sizes, &frame_count,
- ctx->decrypt_cb, ctx->decrypt_state);
+ 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;