/**********
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This library is free software; you can redistribute it and/or modify it under
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the terms of the GNU Lesser General Public License as published by the
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Free Software Foundation; either version 3 of the License, or (at your
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option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)
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This library is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
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more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this library; if not, write to the Free Software Foundation, Inc.,
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51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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**********/
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// "liveMedia"
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// Copyright (c) 1996-2017 Live Networks, Inc. All rights reserved.
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// A filter that breaks up an H263 video stream into frames.
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// derived from MPEG4IP h263.c
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// Author Benhard Feiten
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#ifndef _H263PLUS_VIDEO_STREAM_PARSER_HH
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#define _H263PLUS_VIDEO_STREAM_PARSER_HH
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#ifndef _STREAM_PARSER_HH
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#include "StreamParser.hh"
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#endif
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// Default timescale for H.263 (1000ms)
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#define H263_TIMESCALE 1000
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// Default H263 frame rate (30fps)
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#define H263_BASIC_FRAME_RATE 30
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// Minimum number of bytes needed to parse an H263 header
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#define H263_REQUIRE_HEADER_SIZE_BYTES 5
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// Number of bytes the start code requries
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#define H263_STARTCODE_SIZE_BYTES 3
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// This is the input buffer's size. It should contain
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// 1 frame with the following start code
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#define H263_BUFFER_SIZE 256 * 1024
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// additionalBytesNeeded - indicates how many additional bytes are to be read
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// from the next frame's header (over the 3 bytes that are already read).
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#define ADDITIONAL_BYTES_NEEDED H263_REQUIRE_HEADER_SIZE_BYTES - H263_STARTCODE_SIZE_BYTES
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// The default max different (in %) betwqeen max and average bitrates
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#define H263_DEFAULT_CBR_TOLERANCE 10
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// The following structure holds information extracted from each frame's header:
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typedef struct _H263INFO {
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u_int8_t tr; // Temporal Reference, used in duration calculation
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u_int16_t width; // Width of the picture
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u_int16_t height; // Height of the picture
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bool isSyncFrame; // Frame type (true = I frame = "sync" frame)
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} H263INFO;
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typedef struct _MaxBitrate_CTX {
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u_int32_t bitrateTable[H263_BASIC_FRAME_RATE];// Window of 1 second
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u_int32_t windowBitrate; // The bitrate of the current window
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u_int32_t maxBitrate; // The up-to-date maximum bitrate
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u_int32_t tableIndex; // The next TR unit to update
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} MaxBitrate_CTX;
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class H263plusVideoStreamParser : public StreamParser {
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public:
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H263plusVideoStreamParser( class H263plusVideoStreamFramer* usingSource,
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FramedSource* inputSource);
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virtual ~H263plusVideoStreamParser();
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void registerReadInterest(unsigned char* to, unsigned maxSize);
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unsigned parse(u_int64_t & currentDuration); // returns the size of the frame that was acquired, or 0 if none
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unsigned numTruncatedBytes() const { return fNumTruncatedBytes; } // The number of truncated bytes (if any)
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protected:
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// H263plusVideoStreamFramer* usingSource() {
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// return (H263plusVideoStreamFramer*)fUsingSource;
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// }
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void setParseState();
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// void setParseState(H263plusParseState parseState);
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private:
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int parseH263Frame( );
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bool ParseShortHeader(u_int8_t *headerBuffer, H263INFO *outputInfoStruct);
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void GetMaxBitrate( MaxBitrate_CTX *ctx, u_int32_t frameSize, u_int8_t frameTRDiff);
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u_int64_t CalculateDuration(u_int8_t trDiff);
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bool GetWidthAndHeight( u_int8_t fmt, u_int16_t *width, u_int16_t *height);
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u_int8_t GetTRDifference( u_int8_t nextTR, u_int8_t currentTR);
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virtual void restoreSavedParserState();
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protected:
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class H263plusVideoStreamFramer* fUsingSource;
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unsigned char* fTo;
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unsigned fMaxSize;
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unsigned char* fStartOfFrame;
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unsigned char* fSavedTo;
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unsigned char* fLimit;
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unsigned fNumTruncatedBytes;
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unsigned fSavedNumTruncatedBytes;
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private:
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H263INFO fNextInfo; // Holds information about the next frame
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H263INFO fCurrentInfo; // Holds information about the current frame
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MaxBitrate_CTX fMaxBitrateCtx; // Context for the GetMaxBitrate function
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char fStates[3][256];
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u_int8_t fNextHeader[H263_REQUIRE_HEADER_SIZE_BYTES];
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u_int32_t fnextTR; // The next frame's presentation time in TR units
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u_int64_t fcurrentPT; // The current frame's presentation time in milli-seconds
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};
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#endif
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