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Diffstat (limited to 'drivers/webpold/dec/webpi.h')
| -rw-r--r-- | drivers/webpold/dec/webpi.h | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/drivers/webpold/dec/webpi.h b/drivers/webpold/dec/webpi.h new file mode 100644 index 0000000000..44e5744411 --- /dev/null +++ b/drivers/webpold/dec/webpi.h @@ -0,0 +1,114 @@ +// Copyright 2011 Google Inc. All Rights Reserved. +// +// This code is licensed under the same terms as WebM: +// Software License Agreement: http://www.webmproject.org/license/software/ +// Additional IP Rights Grant: http://www.webmproject.org/license/additional/ +// ----------------------------------------------------------------------------- +// +// Internal header: WebP decoding parameters and custom IO on buffer +// +// Author: somnath@google.com (Somnath Banerjee) + +#ifndef WEBP_DEC_WEBPI_H_ +#define WEBP_DEC_WEBPI_H_ + +#if defined(__cplusplus) || defined(c_plusplus) +extern "C" { +#endif + +#include "../utils/rescaler.h" +#include "./decode_vp8.h" + +//------------------------------------------------------------------------------ +// WebPDecParams: Decoding output parameters. Transient internal object. + +typedef struct WebPDecParams WebPDecParams; +typedef int (*OutputFunc)(const VP8Io* const io, WebPDecParams* const p); +typedef int (*OutputRowFunc)(WebPDecParams* const p, int y_pos); + +struct WebPDecParams { + WebPDecBuffer* output; // output buffer. + uint8_t* tmp_y, *tmp_u, *tmp_v; // cache for the fancy upsampler + // or used for tmp rescaling + + int last_y; // coordinate of the line that was last output + const WebPDecoderOptions* options; // if not NULL, use alt decoding features + // rescalers + WebPRescaler scaler_y, scaler_u, scaler_v, scaler_a; + void* memory; // overall scratch memory for the output work. + + OutputFunc emit; // output RGB or YUV samples + OutputFunc emit_alpha; // output alpha channel + OutputRowFunc emit_alpha_row; // output one line of rescaled alpha values +}; + +// Should be called first, before any use of the WebPDecParams object. +void WebPResetDecParams(WebPDecParams* const params); + +//------------------------------------------------------------------------------ +// Header parsing helpers + +// Structure storing a description of the RIFF headers. +typedef struct { + const uint8_t* data; // input buffer + size_t data_size; // input buffer size + size_t offset; // offset to main data chunk (VP8 or VP8L) + const uint8_t* alpha_data; // points to alpha chunk (if present) + size_t alpha_data_size; // alpha chunk size + size_t compressed_size; // VP8/VP8L compressed data size + size_t riff_size; // size of the riff payload (or 0 if absent) + int is_lossless; // true if a VP8L chunk is present +} WebPHeaderStructure; + +// Skips over all valid chunks prior to the first VP8/VP8L frame header. +// Returns VP8_STATUS_OK on success, +// VP8_STATUS_BITSTREAM_ERROR if an invalid header/chunk is found, and +// VP8_STATUS_NOT_ENOUGH_DATA if case of insufficient data. +// In 'headers', compressed_size, offset, alpha_data, alpha_size and lossless +// fields are updated appropriately upon success. +VP8StatusCode WebPParseHeaders(WebPHeaderStructure* const headers); + +//------------------------------------------------------------------------------ +// Misc utils + +// Initializes VP8Io with custom setup, io and teardown functions. The default +// hooks will use the supplied 'params' as io->opaque handle. +void WebPInitCustomIo(WebPDecParams* const params, VP8Io* const io); + +// Setup crop_xxx fields, mb_w and mb_h in io. 'src_colorspace' refers +// to the *compressed* format, not the output one. +int WebPIoInitFromOptions(const WebPDecoderOptions* const options, + VP8Io* const io, WEBP_CSP_MODE src_colorspace); + +//------------------------------------------------------------------------------ +// Internal functions regarding WebPDecBuffer memory (in buffer.c). +// Don't really need to be externally visible for now. + +// Prepare 'buffer' with the requested initial dimensions width/height. +// If no external storage is supplied, initializes buffer by allocating output +// memory and setting up the stride information. Validate the parameters. Return +// an error code in case of problem (no memory, or invalid stride / size / +// dimension / etc.). If *options is not NULL, also verify that the options' +// parameters are valid and apply them to the width/height dimensions of the +// output buffer. This takes cropping / scaling / rotation into account. +VP8StatusCode WebPAllocateDecBuffer(int width, int height, + const WebPDecoderOptions* const options, + WebPDecBuffer* const buffer); + +// Copy 'src' into 'dst' buffer, making sure 'dst' is not marked as owner of the +// memory (still held by 'src'). +void WebPCopyDecBuffer(const WebPDecBuffer* const src, + WebPDecBuffer* const dst); + +// Copy and transfer ownership from src to dst (beware of parameter order!) +void WebPGrabDecBuffer(WebPDecBuffer* const src, WebPDecBuffer* const dst); + + + +//------------------------------------------------------------------------------ + +#if defined(__cplusplus) || defined(c_plusplus) +} // extern "C" +#endif + +#endif /* WEBP_DEC_WEBPI_H_ */ |