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https://github.com/webmproject/libwebp.git
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VP8GetInfo() + WebPResetDecParams()
- add an internal VP8GetInfo() to parse header - add WebPResetDecParams() for proper initialization Change-Id: Ic39ea634d1d8016d25bdcfef2cb0d00b6dad83e9
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@ -429,6 +429,8 @@ WebPIDecoder* WebPINew(WEBP_CSP_MODE mode) {
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}
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idec->state_ = STATE_HEADER;
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WebPResetDecParams(&idec->params_);
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idec->params_.mode = mode;
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InitMemBuffer(&idec->mem_);
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@ -74,6 +74,44 @@ int VP8SetError(VP8Decoder* const dec,
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return 0;
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}
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//-----------------------------------------------------------------------------
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int VP8GetInfo(const uint8_t* data, uint32_t chunk_size,
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int *width, int *height) {
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// check signature
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if (data[3] != 0x9d || data[4] != 0x01 || data[5] != 0x2a) {
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return 0; // Wrong signature.
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} else {
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const uint32_t bits = data[0] | (data[1] << 8) | (data[2] << 16);
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const int key_frame = !(bits & 1);
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const int w = ((data[7] << 8) | data[6]) & 0x3fff;
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const int h = ((data[9] << 8) | data[8]) & 0x3fff;
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if (!key_frame) { // Not a keyframe.
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return 0;
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}
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if (((bits >> 1) & 7) > 3) {
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return 0; // unknown profile
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}
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if (!((bits >> 4) & 1)) {
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return 0; // first frame is invisible!
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}
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if (((bits >> 5)) >= chunk_size) { // partition_length
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return 0; // inconsistent size information.
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}
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if (width) {
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*width = w;
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}
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if (height) {
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*height = h;
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}
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return 1;
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}
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}
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//-----------------------------------------------------------------------------
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// Header parsing
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@ -263,6 +263,11 @@ struct VP8Decoder {
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// in vp8.c
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int VP8SetError(VP8Decoder* const dec,
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VP8StatusCode error, const char * const msg);
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// Validates the VP8 data-header and retrieve basic header information viz width
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// and height. Returns 0 in case of formatting error. *width/*height can be
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// passed NULL.
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int VP8GetInfo(const uint8_t* data, uint32_t data_size,
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int *width, int *height);
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// in tree.c
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void VP8ResetProba(VP8Proba* const proba);
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@ -414,18 +414,23 @@ int WebPCheckDecParams(const VP8Io* io, const WebPDecParams* params) {
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return ok;
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}
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void WebPResetDecParams(WebPDecParams* const params) {
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assert(params);
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memset(params, 0, sizeof(*params));
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}
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void WebPClearDecParams(WebPDecParams* params) {
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assert(params);
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if (!params->external_buffer) {
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free(params->output);
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}
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memset(params, 0, sizeof(*params));
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WebPResetDecParams(params);
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}
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//-----------------------------------------------------------------------------
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// "Into" variants
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static uint8_t* DecodeInto(WEBP_CSP_MODE mode,
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const uint8_t* data, uint32_t data_size,
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static uint8_t* DecodeInto(const uint8_t* data, uint32_t data_size,
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WebPDecParams* params) {
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VP8Decoder* dec = VP8New();
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VP8Io io;
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@ -439,7 +444,6 @@ static uint8_t* DecodeInto(WEBP_CSP_MODE mode,
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io.data = data;
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io.data_size = data_size;
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params->mode = mode;
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io.opaque = params;
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WebPInitCustomIo(&io);
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@ -455,7 +459,7 @@ static uint8_t* DecodeInto(WEBP_CSP_MODE mode,
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return NULL;
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}
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if (mode != MODE_YUV) {
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if (params->mode != MODE_YUV) {
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VP8YUVInit();
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}
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@ -473,12 +477,12 @@ uint8_t* WebPDecodeRGBInto(const uint8_t* data, uint32_t data_size,
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return NULL;
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}
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WebPResetDecParams(¶ms);
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params.mode = MODE_RGB;
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params.output = output;
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params.stride = output_stride;
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params.output_size = output_size;
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params.output_u_size = 0;
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params.output_v_size = 0;
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return DecodeInto(MODE_RGB, data, data_size, ¶ms);
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return DecodeInto(data, data_size, ¶ms);
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}
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uint8_t* WebPDecodeRGBAInto(const uint8_t* data, uint32_t data_size,
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@ -490,12 +494,12 @@ uint8_t* WebPDecodeRGBAInto(const uint8_t* data, uint32_t data_size,
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return NULL;
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}
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WebPResetDecParams(¶ms);
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params.mode = MODE_RGBA;
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params.output = output;
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params.stride = output_stride;
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params.output_size = output_size;
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params.output_u_size = 0;
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params.output_v_size = 0;
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return DecodeInto(MODE_RGBA, data, data_size, ¶ms);
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return DecodeInto(data, data_size, ¶ms);
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}
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uint8_t* WebPDecodeBGRInto(const uint8_t* data, uint32_t data_size,
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@ -507,12 +511,12 @@ uint8_t* WebPDecodeBGRInto(const uint8_t* data, uint32_t data_size,
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return NULL;
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}
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WebPResetDecParams(¶ms);
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params.mode = MODE_BGR;
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params.output = output;
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params.stride = output_stride;
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params.output_size = output_size;
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params.output_u_size = 0;
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params.output_v_size = 0;
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return DecodeInto(MODE_BGR, data, data_size, ¶ms);
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return DecodeInto(data, data_size, ¶ms);
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}
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uint8_t* WebPDecodeBGRAInto(const uint8_t* data, uint32_t data_size,
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@ -524,12 +528,12 @@ uint8_t* WebPDecodeBGRAInto(const uint8_t* data, uint32_t data_size,
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return NULL;
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}
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WebPResetDecParams(¶ms);
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params.mode = MODE_BGRA;
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params.output = output;
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params.stride = output_stride;
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params.output_size = output_size;
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params.output_u_size = 0;
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params.output_v_size = 0;
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return DecodeInto(MODE_BGRA, data, data_size, ¶ms);
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return DecodeInto(data, data_size, ¶ms);
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}
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uint8_t* WebPDecodeYUVInto(const uint8_t* data, uint32_t data_size,
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@ -542,6 +546,8 @@ uint8_t* WebPDecodeYUVInto(const uint8_t* data, uint32_t data_size,
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return NULL;
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}
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WebPResetDecParams(¶ms);
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params.mode = MODE_YUV;
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params.output = luma;
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params.stride = luma_stride;
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params.output_size = luma_size;
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@ -551,7 +557,7 @@ uint8_t* WebPDecodeYUVInto(const uint8_t* data, uint32_t data_size,
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params.v = v;
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params.v_stride = v_stride;
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params.output_v_size = v_size;
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return DecodeInto(MODE_YUV, data, data_size, ¶ms);
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return DecodeInto(data, data_size, ¶ms);
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}
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//-----------------------------------------------------------------------------
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@ -562,7 +568,7 @@ static uint8_t* Decode(WEBP_CSP_MODE mode, const uint8_t* data,
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uint8_t* output;
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WebPDecParams params;
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memset(¶ms, 0, sizeof(params));
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WebPResetDecParams(¶ms);
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params.mode = mode;
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if (!WebPInitDecParams(data, data_size, width, height, ¶ms)) {
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return NULL;
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@ -571,7 +577,7 @@ static uint8_t* Decode(WEBP_CSP_MODE mode, const uint8_t* data,
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params.output_size = params.stride * (*height);
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params.output_u_size = params.output_v_size =
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params.u_stride * ((*height + 1) / 2);
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output = DecodeInto(mode, data, data_size, ¶ms);
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output = DecodeInto(data, data_size, ¶ms);
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if (!output) {
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WebPClearDecParams(¶ms);
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}
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@ -631,38 +637,7 @@ int WebPGetInfo(const uint8_t* data, uint32_t data_size,
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if (data_size < 10) {
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return 0; // not enough data
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}
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// check signature
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if (data[3] != 0x9d || data[4] != 0x01 || data[5] != 0x2a) {
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return 0; // Wrong signature.
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} else {
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const uint32_t bits = data[0] | (data[1] << 8) | (data[2] << 16);
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const int key_frame = !(bits & 1);
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const int w = ((data[7] << 8) | data[6]) & 0x3fff;
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const int h = ((data[9] << 8) | data[8]) & 0x3fff;
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if (!key_frame) { // Not a keyframe.
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return 0;
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}
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if (((bits >> 1) & 7) > 3) {
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return 0; // unknown profile
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}
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if (!((bits >> 4) & 1)) {
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return 0; // first frame is invisible!
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}
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if (((bits >> 5)) >= chunk_size) { // partition_length
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return 0; // inconsistent size information.
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}
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if (width) {
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*width = w;
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}
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if (height) {
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*height = h;
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}
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return 1;
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}
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return VP8GetInfo(data, chunk_size, width, height);
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}
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#if defined(__cplusplus) || defined(c_plusplus)
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@ -34,6 +34,9 @@ typedef struct {
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int external_buffer; // If true, the output buffers are externally owned
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} WebPDecParams;
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// Should be called first, before any use of the WebPDecParams object.
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void WebPResetDecParams(WebPDecParams* const params);
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// If a RIFF container is detected, validate it and skip over it. Returns
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// VP8 bit-stream size if RIFF header is valid else returns 0
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uint32_t WebPCheckRIFFHeader(const uint8_t** data_ptr,
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