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reorganize chunk-parsing code

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make room for future VP8X extensions

Change-Id: Ic78217c26f142403b733740b17980aa81602f83d
This commit is contained in:
Pascal Massimino
2011-08-18 11:07:13 -07:00
parent 3cf2030653
commit dfcc2136e1
5 changed files with 245 additions and 86 deletions
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137
src/dec/vp8.c
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@ -11,11 +11,15 @@
#include <stdlib.h>
#include "vp8i.h"
#include "webpi.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
#define RIFF_HEADER_SIZE 12
#define VP8X_HEADER_SIZE 20
//-----------------------------------------------------------------------------
int WebPGetDecoderVersion(void) {
@ -77,8 +81,40 @@ int VP8SetError(VP8Decoder* const dec,
//-----------------------------------------------------------------------------
int VP8GetInfo(const uint8_t* data,
uint32_t data_size, uint32_t chunk_size,
static inline uint32_t get_le32(const uint8_t* const data) {
return data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
}
int VP8CheckAndSkipHeader(const uint8_t** data_ptr, uint32_t* data_size_ptr,
int* is_vp8_chunk, uint32_t* chunk_size,
uint32_t riff_size) {
if (!data_ptr || !data_size_ptr || !is_vp8_chunk || !chunk_size) {
return 0; // Invalid Args.
}
if (*data_size_ptr >= 8) {
if (!memcmp(*data_ptr, "VP8 ", 4)) {
*is_vp8_chunk = 1;
*chunk_size = get_le32(*data_ptr + 4);
if ((riff_size >= RIFF_HEADER_SIZE) &&
(*chunk_size > riff_size - RIFF_HEADER_SIZE)) {
return 0; // Inconsistent size information.
}
// We have consumed 8 bytes from VP8 Header. Skip it.
*data_ptr += 8;
*data_size_ptr -= 8;
} else {
*is_vp8_chunk = 0;
*chunk_size = 0;
}
} else {
*is_vp8_chunk = -1; // Insufficient data.
*chunk_size = 0;
}
return 1;
}
int VP8GetInfo(const uint8_t* data, uint32_t data_size, uint32_t chunk_size,
int* width, int* height, int* has_alpha) {
if (data_size < 10) {
return 0; // not enough data
@ -125,6 +161,40 @@ int VP8GetInfo(const uint8_t* data,
}
}
int VP8XGetInfo(const uint8_t** data_ptr, uint32_t* data_size_ptr,
int* is_vp8x_chunk, int* width, int* height, uint32_t* flags) {
if (!data_ptr || !data_size_ptr || !is_vp8x_chunk) {
return 0; // Invalid Args.
}
if (*data_size_ptr >= VP8X_HEADER_SIZE) {
if (!memcmp(*data_ptr, "VP8X", 4)) {
const uint32_t chunk_size = get_le32(*data_ptr + 4);
*is_vp8x_chunk = 1;
if (chunk_size != (VP8X_HEADER_SIZE - 8)) {
return 0; // Wrong chunk size.
}
if (flags) {
*flags = get_le32(*data_ptr + 8);
}
if (width) {
*width = get_le32(*data_ptr + 12);
}
if (height) {
*height = get_le32(*data_ptr + 16);
}
// We have consumed 20 bytes from VP8X Header. Skip it.
*data_ptr += VP8X_HEADER_SIZE;
*data_size_ptr -= VP8X_HEADER_SIZE;
} else {
*is_vp8x_chunk = 0;
}
} else {
*is_vp8x_chunk = -1; // Insufficient data.
}
return 1;
}
//-----------------------------------------------------------------------------
// Header parsing
@ -245,14 +315,14 @@ static int ParseFilterHeader(VP8BitReader* br, VP8Decoder* const dec) {
return !br->eof_;
}
static inline uint32_t get_le32(const uint8_t* const data) {
return data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
}
// Topmost call
int VP8GetHeaders(VP8Decoder* const dec, VP8Io* const io) {
uint8_t* buf;
const uint8_t* buf;
uint32_t buf_size;
uint32_t riff_size;
uint32_t chunk_size;
int is_vp8x_chunk = 0;
int is_vp8_chunk = 0;
VP8FrameHeader* frm_hdr;
VP8PictureHeader* pic_hdr;
VP8BitReader* br;
@ -274,34 +344,31 @@ int VP8GetHeaders(VP8Decoder* const dec, VP8Io* const io) {
"Not enough data to parse frame header");
}
// Skip over valid RIFF headers
if (!memcmp(buf, "RIFF", 4)) {
uint32_t riff_size;
uint32_t chunk_size;
if (buf_size < 20 + 4) {
return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
"RIFF: Truncated header.");
}
if (memcmp(buf + 8, "WEBP", 4)) { // wrong image file signature
// Skip over valid RIFF headers.
if (!WebPCheckAndSkipRIFFHeader(&buf, &buf_size, &riff_size)) {
return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
"RIFF: Invalid RIFF container");
}
if (!VP8XGetInfo(&buf, &buf_size, &is_vp8x_chunk, NULL, NULL, NULL)) {
return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
"RIFF: Invalid VP8X container");
}
if (!VP8CheckAndSkipHeader(&buf, &buf_size, &is_vp8_chunk, &chunk_size,
riff_size)) {
return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
"RIFF: Inconsistent size information.");
}
if (is_vp8_chunk == -1) {
return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
"RIFF: WEBP signature not found.");
}
riff_size = get_le32(buf + 4);
if (riff_size < 12) {
return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
"RIFF: Truncated header.");
}
if (memcmp(buf + 12, "VP8 ", 4)) {
return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
"RIFF: Invalid compression format.");
}
chunk_size = get_le32(buf + 16);
if (chunk_size > riff_size - 12) {
return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
"RIFF: Inconsistent size information.");
}
buf += 20;
buf_size -= 20;
"Not enough data to parse frame header.");
}
if (buf_size < 4) {
return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
"RIFF: Truncated header.");
}
// Paragraph 9.1
@ -437,7 +504,7 @@ int VP8GetHeaders(VP8Decoder* const dec, VP8Io* const io) {
if (dec->pic_hdr_.colorspace_) {
const size_t kTrailerSize = 8;
const uint8_t kTrailerMarker = 0x01;
uint8_t* const ext_buf = buf - kTrailerSize;
const uint8_t* ext_buf = buf - kTrailerSize;
size_t size;
if (frm_hdr->partition_length_ < kTrailerSize ||