gstreamer/ext/mplex/mpegconsts.h

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/*
* mpegconsts.c: Video format constants for MPEG and utilities for display
* and conversion to format used for yuv4mpeg
*
* Copyright (C) 2001 Andrew Stevens <andrew.stevens@philips.com>
*
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public License
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifndef __MPEGCONSTS_H__
#define __MPEGCONSTS_H__
#include "yuv4mpeg.h"
typedef unsigned int mpeg_framerate_code_t;
typedef unsigned int mpeg_aspect_code_t;
extern const mpeg_framerate_code_t mpeg_num_framerates;
extern const mpeg_aspect_code_t mpeg_num_aspect_ratios[2];
#ifdef __cplusplus
extern "C" {
#endif
/*
* Convert MPEG frame-rate code to corresponding frame-rate
* y4m_fps_UNKNOWN = { 0, 0 } = Undefined/resrerved code.
*/
y4m_ratio_t
mpeg_framerate( mpeg_framerate_code_t code );
/*
* Look-up MPEG frame rate code for a (exact) frame rate.
* 0 = No MPEG code defined for frame-rate
*/
mpeg_framerate_code_t
mpeg_framerate_code( y4m_ratio_t framerate );
/*
* Convert floating-point framerate to an exact ratio.
* Uses a standard MPEG rate, if it finds one within MPEG_FPS_TOLERANCE
* (see mpegconsts.c), otherwise uses "fps:1000000" as the ratio.
*/
y4m_ratio_t
mpeg_conform_framerate( double fps );
/*
* Convert MPEG aspect ratio code to corresponding aspect ratio
*
* WARNING: The semantics of aspect ratio coding *changed* between
* MPEG1 and MPEG2. In MPEG1 it is the *pixel* aspect ratio. In
* MPEG2 it is the (far more sensible) aspect ratio of the eventual
* display.
*
*/
y4m_ratio_t
mpeg_aspect_ratio( int mpeg_version, mpeg_aspect_code_t code );
/*
* Look-up MPEG aspect ratio code for an aspect ratio - tolerance
* is Y4M_ASPECT_MULT used by YUV4MPEG (see yuv4mpeg_intern.h)
*
* WARNING: The semantics of aspect ratio coding *changed* between
* MPEG1 and MPEG2. In MPEG1 it is the *pixel* aspect ratio. In
* MPEG2 it is the (far more sensible) aspect ratio of the eventual
* display.
*
*/
mpeg_aspect_code_t
mpeg_frame_aspect_code( int mpeg_version, y4m_ratio_t aspect_ratio );
/*
* Look-up MPEG explanatory definition string aspect ratio code for an
* aspect ratio code
*
*/
const char *
mpeg_aspect_code_definition( int mpeg_version, mpeg_aspect_code_t code );
/*
* Look-up MPEG explanatory definition string aspect ratio code for an
* frame rate code
*
*/
const char *
mpeg_framerate_code_definition( mpeg_framerate_code_t code );
const char *
mpeg_interlace_code_definition( int yuv4m_interlace_code );
/*
* Guess the correct MPEG aspect ratio code,
* given the true sample aspect ratio and frame size of a video stream
* (and the MPEG version, 1 or 2).
*
* Returns 0 if it has no good answer.
*
*/
mpeg_aspect_code_t
mpeg_guess_mpeg_aspect_code(int mpeg_version, y4m_ratio_t sampleaspect,
int frame_width, int frame_height);
/*
* Guess the true sample aspect ratio of a video stream,
* given the MPEG aspect ratio code and the actual frame size
* (and the MPEG version, 1 or 2).
*
* Returns y4m_sar_UNKNOWN if it has no good answer.
*
*/
y4m_ratio_t
mpeg_guess_sample_aspect_ratio(int mpeg_version,
mpeg_aspect_code_t code,
int frame_width, int frame_height);
#ifdef __cplusplus
};
#endif
#endif /* __MPEGCONSTS_H__ */