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c398f59536
- Add alpha support in mux. - Remove WebPMuxAddNamedData() and WebPMuxGetNamedData() APIs. Add WebPMuxSetImage(), WebPmuxGetImage() and WebPMuxDeleteImage() APIs instead. - Refactor code using WebPImage struct. - Corresponding changes in webpmux binary. - WebPMuxSetImage()/AddFrame()/AddTile() can now work with data which starts from "RIFF...". This simplifies reading a single-image webp file and adding it as an image/frame/tile in mux. Change-Id: I7d98a6407dfe55c84a682ef7e46bc622f5a6f8d9
119 lines
3.7 KiB
Plaintext
119 lines
3.7 KiB
Plaintext
__ __ ____ ____ ____ __ __ _ __ __
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/ \\/ \/ _ \/ _ \/ _ \/ \ \/ \___/_ / _\
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\ / __/ _ \ __/ / / (_/ /__
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\__\__/\_____/_____/__/ \__//_/\_____/__/___/
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Description:
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============
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WebP Mux: library to create the MUX container object for features like
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Color profile, XMP metadata, Animation & Tiling. A reference command line
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tool 'webpmux' and Mux container specification 'MuxContainerSpec.pdf' are also
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provided in this package.
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WebP Mux tool:
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==============
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The examples/ directory contains tool (webpmux) for manipulating the WebP Mux
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file. webpmux tool can be used to create a WebP container file and to extract or
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strip relevant data from the container file.
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A list of options is available using the -help command line flag:
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> webpmux -help
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Usage: webpmux -get GET_OPTIONS INPUT -o OUTPUT
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or: webpmux -set SET_OPTIONS INPUT -o OUTPUT
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or: webpmux -strip STRIP_OPTIONS INPUT -o OUTPUT
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or: webpmux [-tile TILE_OPTIONS]... -o OUTPUT
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or: webpmux [-frame FRAME_OPTIONS]... -loop LOOP_COUNT -o OUTPUT
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or: webpmux -info INPUT
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or: webpmux -help OR -h
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GET_OPTIONS:
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icc Get ICCP Color profile.
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xmp Get XMP metadata.
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tile n Get nth tile.
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frame n Get nth frame.
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SET_OPTIONS:
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icc Set ICC Color profile.
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xmp Set XMP metadata.
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STRIP_OPTIONS:
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icc Strip ICCP color profile.
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xmp Strip XMP metadata.
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TILE_OPTIONS(i):
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file_i +xi+yi
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where: 'file_i' is the i'th tile (webp format),
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'xi','yi' specify the image offset for this tile.
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FRAME_OPTIONS(i):
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file_i +xi+yi+di
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where: 'file_i' is the i'th animation frame (webp format),
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'xi','yi' specify the image offset for this frame.
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'di' is the pause duration before next frame.
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INPUT & OUTPUT are in webp format.
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WebP Mux API:
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==============
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WebP Mux API contains methods for adding data to WebPMux (a MUX container object
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for a WebP file) and reading data from WebPMux. This API currently supports
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XMP metadata, Color profile, Animation & Tiling. Other features will be added
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in subsequent releases.
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Example#1 (pseudo code): Creating a MUX with image data, color profile & XMP
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metadata.
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int copy_data = 0;
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WebPMux* mux = WebPMuxNew();
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// ... (Prepare image data).
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WebPMuxSetImage(mux, image_data, image_data_size, alpha_data, alpha_size,
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copy_data);
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// ... (Prepare ICCP color profile data).
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WebPMuxSetColorProfile(mux, icc_data, icc_data_size, copy_data);
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// ... (Prepare XMP metadata).
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WebPMuxSetMetadata(mux, xmp_data, xmp_data_size, copy_data);
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// Get data from mux in WebP RIFF format.
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WebPMuxAssemble(mux, &output_data, &output_data_size);
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WebPMuxDelete(mux);
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// ... (Consume output_data; e.g. write output_data to file).
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free(output_data);
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Example#2 (pseudo code): Get image & color profile data from a WebP file.
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int copy_data = 0;
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// ... (Read data from file).
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WebPMux* mux = WebPMuxCreate(data, data_size, copy_data);
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WebPMuxGetImage(mux, &image_data, &image_data_size,
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&alpha_data, &alpha_size);
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// ... (Consume image_data; e.g. call WebPDecode() to decode the data).
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WebPMuxGetColorProfile(mux, &icc_data, &icc_data_size);
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// ... (Consume icc_data).
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WebPMuxDelete(mux);
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free(data);
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For detailed MUX-API reference, please refer to the header file (src/webp/mux.h)
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Bugs:
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=====
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Please report all bugs to our issue tracker:
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http://code.google.com/p/webp/issues
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Patches welcome! See this page to get started:
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http://www.webmproject.org/code/contribute/submitting-patches/
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Discuss:
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========
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Email: webp-discuss@webmproject.org
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Web: http://groups.google.com/a/webmproject.org/group/webp-discuss
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