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+/********************************************************************
+ * *
+ * THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE. *
+ * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
+ * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
+ * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
+ * *
+ * THE Theora SOURCE CODE IS COPYRIGHT (C) 2002-2009 *
+ * by the Xiph.Org Foundation http://www.xiph.org/ *
+ * *
+ ********************************************************************
+
+ function:
+ last mod: $Id: theora.h,v 1.8 2004/03/15 22:17:32 derf Exp $
+
+ ********************************************************************/
+
+/**\file
+ * The <tt>libtheoradec</tt> C decoding API.*/
+
+#if !defined(_O_THEORA_THEORADEC_H_)
+# define _O_THEORA_THEORADEC_H_ (1)
+# include <stddef.h>
+# include <ogg/ogg.h>
+# include "codec.h"
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+
+
+/**\name th_decode_ctl() codes
+ * \anchor decctlcodes
+ * These are the available request codes for th_decode_ctl().
+ * By convention, these are odd, to distinguish them from the
+ * \ref encctlcodes "encoder control codes".
+ * Keep any experimental or vendor-specific values above \c 0x8000.*/
+/*@{*/
+/**Gets the maximum post-processing level.
+ * The decoder supports a post-processing filter that can improve
+ * the appearance of the decoded images. This returns the highest
+ * level setting for this post-processor, corresponding to maximum
+ * improvement and computational expense.
+ *
+ * \param[out] _buf int: The maximum post-processing level.
+ * \retval TH_EFAULT \a _dec_ctx or \a _buf is <tt>NULL</tt>.
+ * \retval TH_EINVAL \a _buf_sz is not <tt>sizeof(int)</tt>.
+ * \retval TH_EIMPL Not supported by this implementation.*/
+#define TH_DECCTL_GET_PPLEVEL_MAX (1)
+/**Sets the post-processing level.
+ * By default, post-processing is disabled.
+ *
+ * Sets the level of post-processing to use when decoding the
+ * compressed stream. This must be a value between zero (off)
+ * and the maximum returned by TH_DECCTL_GET_PPLEVEL_MAX.
+ *
+ * \param[in] _buf int: The new post-processing level.
+ * 0 to disable; larger values use more CPU.
+ * \retval TH_EFAULT \a _dec_ctx or \a _buf is <tt>NULL</tt>.
+ * \retval TH_EINVAL \a _buf_sz is not <tt>sizeof(int)</tt>, or the
+ * post-processing level is out of bounds.
+ * The maximum post-processing level may be
+ * implementation-specific, and can be obtained via
+ * #TH_DECCTL_GET_PPLEVEL_MAX.
+ * \retval TH_EIMPL Not supported by this implementation.*/
+#define TH_DECCTL_SET_PPLEVEL (3)
+/**Sets the granule position.
+ * Call this after a seek, before decoding the first frame, to ensure that the
+ * proper granule position is returned for all subsequent frames.
+ * If you track timestamps yourself and do not use the granule position
+ * returned by the decoder, then you need not call this function.
+ *
+ * \param[in] _buf <tt>ogg_int64_t</tt>: The granule position of the next
+ * frame.
+ * \retval TH_EFAULT \a _dec_ctx or \a _buf is <tt>NULL</tt>.
+ * \retval TH_EINVAL \a _buf_sz is not <tt>sizeof(ogg_int64_t)</tt>, or the
+ * granule position is negative.*/
+#define TH_DECCTL_SET_GRANPOS (5)
+/**Sets the striped decode callback function.
+ * If set, this function will be called as each piece of a frame is fully
+ * decoded in th_decode_packetin().
+ * You can pass in a #th_stripe_callback with
+ * th_stripe_callback#stripe_decoded set to <tt>NULL</tt> to disable the
+ * callbacks at any point.
+ * Enabling striped decode does not prevent you from calling
+ * th_decode_ycbcr_out() after the frame is fully decoded.
+ *
+ * \param[in] _buf #th_stripe_callback: The callback parameters.
+ * \retval TH_EFAULT \a _dec_ctx or \a _buf is <tt>NULL</tt>.
+ * \retval TH_EINVAL \a _buf_sz is not
+ * <tt>sizeof(th_stripe_callback)</tt>.*/
+#define TH_DECCTL_SET_STRIPE_CB (7)
+
+/**Sets the macroblock display mode. Set to 0 to disable displaying
+ * macroblocks.*/
+#define TH_DECCTL_SET_TELEMETRY_MBMODE (9)
+/**Sets the motion vector display mode. Set to 0 to disable displaying motion
+ * vectors.*/
+#define TH_DECCTL_SET_TELEMETRY_MV (11)
+/**Sets the adaptive quantization display mode. Set to 0 to disable displaying
+ * adaptive quantization. */
+#define TH_DECCTL_SET_TELEMETRY_QI (13)
+/**Sets the bitstream breakdown visualization mode. Set to 0 to disable
+ * displaying bitstream breakdown.*/
+#define TH_DECCTL_SET_TELEMETRY_BITS (15)
+/*@}*/
+
+
+
+/**A callback function for striped decode.
+ * This is a function pointer to an application-provided function that will be
+ * called each time a section of the image is fully decoded in
+ * th_decode_packetin().
+ * This allows the application to process the section immediately, while it is
+ * still in cache.
+ * Note that the frame is decoded bottom to top, so \a _yfrag0 will steadily
+ * decrease with each call until it reaches 0, at which point the full frame
+ * is decoded.
+ * The number of fragment rows made available in each call depends on the pixel
+ * format and the number of post-processing filters enabled, and may not even
+ * be constant for the entire frame.
+ * If a non-<tt>NULL</tt> \a _granpos pointer is passed to
+ * th_decode_packetin(), the granule position for the frame will be stored
+ * in it before the first callback is made.
+ * If an entire frame is dropped (a 0-byte packet), then no callbacks will be
+ * made at all for that frame.
+ * \param _ctx An application-provided context pointer.
+ * \param _buf The image buffer for the decoded frame.
+ * \param _yfrag0 The Y coordinate of the first row of 8x8 fragments
+ * decoded.
+ * Multiply this by 8 to obtain the pixel row number in the
+ * luma plane.
+ * If the chroma planes are subsampled in the Y direction,
+ * this will always be divisible by two.
+ * \param _yfrag_end The Y coordinate of the first row of 8x8 fragments past
+ * the newly decoded section.
+ * If the chroma planes are subsampled in the Y direction,
+ * this will always be divisible by two.
+ * I.e., this section contains fragment rows
+ * <tt>\a _yfrag0 ...\a _yfrag_end -1</tt>.*/
+typedef void (*th_stripe_decoded_func)(void *_ctx,th_ycbcr_buffer _buf,
+ int _yfrag0,int _yfrag_end);
+
+/**The striped decode callback data to pass to #TH_DECCTL_SET_STRIPE_CB.*/
+typedef struct{
+ /**An application-provided context pointer.
+ * This will be passed back verbatim to the application.*/
+ void *ctx;
+ /**The callback function pointer.*/
+ th_stripe_decoded_func stripe_decoded;
+}th_stripe_callback;
+
+
+
+/**\name Decoder state
+ The following data structures are opaque, and their contents are not
+ publicly defined by this API.
+ Referring to their internals directly is unsupported, and may break without
+ warning.*/
+/*@{*/
+/**The decoder context.*/
+typedef struct th_dec_ctx th_dec_ctx;
+/**Setup information.
+ This contains auxiliary information (Huffman tables and quantization
+ parameters) decoded from the setup header by th_decode_headerin() to be
+ passed to th_decode_alloc().
+ It can be re-used to initialize any number of decoders, and can be freed
+ via th_setup_free() at any time.*/
+typedef struct th_setup_info th_setup_info;
+/*@}*/
+
+
+
+/**\defgroup decfuncs Functions for Decoding*/
+/*@{*/
+/**\name Functions for decoding
+ * You must link to <tt>libtheoradec</tt> if you use any of the
+ * functions in this section.
+ *
+ * The functions are listed in the order they are used in a typical decode.
+ * The basic steps are:
+ * - Parse the header packets by repeatedly calling th_decode_headerin().
+ * - Allocate a #th_dec_ctx handle with th_decode_alloc().
+ * - Call th_setup_free() to free any memory used for codec setup
+ * information.
+ * - Perform any additional decoder configuration with th_decode_ctl().
+ * - For each video data packet:
+ * - Submit the packet to the decoder via th_decode_packetin().
+ * - Retrieve the uncompressed video data via th_decode_ycbcr_out().
+ * - Call th_decode_free() to release all decoder memory.*/
+/*@{*/
+/**Decodes the header packets of a Theora stream.
+ * This should be called on the initial packets of the stream, in succession,
+ * until it returns <tt>0</tt>, indicating that all headers have been
+ * processed, or an error is encountered.
+ * At least three header packets are required, and additional optional header
+ * packets may follow.
+ * This can be used on the first packet of any logical stream to determine if
+ * that stream is a Theora stream.
+ * \param _info A #th_info structure to fill in.
+ * This must have been previously initialized with
+ * th_info_init().
+ * The application may immediately begin using the contents of
+ * this structure after the first header is decoded, though it
+ * must continue to be passed in on all subsequent calls.
+ * \param _tc A #th_comment structure to fill in.
+ * The application may immediately begin using the contents of
+ * this structure after the second header is decoded, though it
+ * must continue to be passed in on all subsequent calls.
+ * \param _setup Returns a pointer to additional, private setup information
+ * needed by the decoder.
+ * The contents of this pointer must be initialized to
+ * <tt>NULL</tt> on the first call, and the returned value must
+ * continue to be passed in on all subsequent calls.
+ * \param _op An <tt>ogg_packet</tt> structure which contains one of the
+ * initial packets of an Ogg logical stream.
+ * \return A positive value indicates that a Theora header was successfully
+ * processed.
+ * \retval 0 The first video data packet was encountered after all
+ * required header packets were parsed.
+ * The packet just passed in on this call should be saved
+ * and fed to th_decode_packetin() to begin decoding
+ * video data.
+ * \retval TH_EFAULT One of \a _info, \a _tc, or \a _setup was
+ * <tt>NULL</tt>.
+ * \retval TH_EBADHEADER \a _op was <tt>NULL</tt>, the packet was not the next
+ * header packet in the expected sequence, or the format
+ * of the header data was invalid.
+ * \retval TH_EVERSION The packet data was a Theora info header, but for a
+ * bitstream version not decodable with this version of
+ * <tt>libtheoradec</tt>.
+ * \retval TH_ENOTFORMAT The packet was not a Theora header.
+ */
+extern int th_decode_headerin(th_info *_info,th_comment *_tc,
+ th_setup_info **_setup,ogg_packet *_op);
+/**Allocates a decoder instance.
+ *
+ * <b>Security Warning:</b> The Theora format supports very large frame sizes,
+ * potentially even larger than the address space of a 32-bit machine, and
+ * creating a decoder context allocates the space for several frames of data.
+ * If the allocation fails here, your program will crash, possibly at some
+ * future point because the OS kernel returned a valid memory range and will
+ * only fail when it tries to map the pages in it the first time they are
+ * used.
+ * Even if it succeeds, you may experience a denial of service if the frame
+ * size is large enough to cause excessive paging.
+ * If you are integrating libtheora in a larger application where such things
+ * are undesirable, it is highly recommended that you check the frame size in
+ * \a _info before calling this function and refuse to decode streams where it
+ * is larger than some reasonable maximum.
+ * libtheora will not check this for you, because there may be machines that
+ * can handle such streams and applications that wish to.
+ * \param _info A #th_info struct filled via th_decode_headerin().
+ * \param _setup A #th_setup_info handle returned via
+ * th_decode_headerin().
+ * \return The initialized #th_dec_ctx handle.
+ * \retval NULL If the decoding parameters were invalid.*/
+extern th_dec_ctx *th_decode_alloc(const th_info *_info,
+ const th_setup_info *_setup);
+/**Releases all storage used for the decoder setup information.
+ * This should be called after you no longer want to create any decoders for
+ * a stream whose headers you have parsed with th_decode_headerin().
+ * \param _setup The setup information to free.
+ * This can safely be <tt>NULL</tt>.*/
+extern void th_setup_free(th_setup_info *_setup);
+/**Decoder control function.
+ * This is used to provide advanced control of the decoding process.
+ * \param _dec A #th_dec_ctx handle.
+ * \param _req The control code to process.
+ * See \ref decctlcodes "the list of available control codes"
+ * for details.
+ * \param _buf The parameters for this control code.
+ * \param _buf_sz The size of the parameter buffer.
+ * \return Possible return values depend on the control code used.
+ * See \ref decctlcodes "the list of control codes" for
+ * specific values. Generally 0 indicates success.*/
+extern int th_decode_ctl(th_dec_ctx *_dec,int _req,void *_buf,
+ size_t _buf_sz);
+/**Submits a packet containing encoded video data to the decoder.
+ * \param _dec A #th_dec_ctx handle.
+ * \param _op An <tt>ogg_packet</tt> containing encoded video data.
+ * \param _granpos Returns the granule position of the decoded packet.
+ * If non-<tt>NULL</tt>, the granule position for this specific
+ * packet is stored in this location.
+ * This is computed incrementally from previously decoded
+ * packets.
+ * After a seek, the correct granule position must be set via
+ * #TH_DECCTL_SET_GRANPOS for this to work properly.
+ * \retval 0 Success.
+ * A new decoded frame can be retrieved by calling
+ * th_decode_ycbcr_out().
+ * \retval TH_DUPFRAME The packet represented a dropped frame (either a
+ * 0-byte frame or an INTER frame with no coded blocks).
+ * The player can skip the call to th_decode_ycbcr_out(),
+ * as the contents of the decoded frame buffer have not
+ * changed.
+ * \retval TH_EFAULT \a _dec or \a _op was <tt>NULL</tt>.
+ * \retval TH_EBADPACKET \a _op does not contain encoded video data.
+ * \retval TH_EIMPL The video data uses bitstream features which this
+ * library does not support.*/
+extern int th_decode_packetin(th_dec_ctx *_dec,const ogg_packet *_op,
+ ogg_int64_t *_granpos);
+/**Outputs the next available frame of decoded Y'CbCr data.
+ * If a striped decode callback has been set with #TH_DECCTL_SET_STRIPE_CB,
+ * then the application does not need to call this function.
+ * \param _dec A #th_dec_ctx handle.
+ * \param _ycbcr A video buffer structure to fill in.
+ * <tt>libtheoradec</tt> will fill in all the members of this
+ * structure, including the pointers to the uncompressed video
+ * data.
+ * The memory for this video data is owned by
+ * <tt>libtheoradec</tt>.
+ * It may be freed or overwritten without notification when
+ * subsequent frames are decoded.
+ * \retval 0 Success
+ * \retval TH_EFAULT \a _dec or \a _ycbcr was <tt>NULL</tt>.
+ */
+extern int th_decode_ycbcr_out(th_dec_ctx *_dec,
+ th_ycbcr_buffer _ycbcr);
+/**Frees an allocated decoder instance.
+ * \param _dec A #th_dec_ctx handle.*/
+extern void th_decode_free(th_dec_ctx *_dec);
+/*@}*/
+/*@}*/
+
+
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif