mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-12-22 16:26:39 +00:00
427 lines
10 KiB
C++
427 lines
10 KiB
C++
|
||
/*
|
||
* 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>
|
||
* Copyright (C) 2001 Matthew Marjanovic <maddog@mir.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.
|
||
*/
|
||
|
||
#include <config.h>
|
||
#include "mpegconsts.h"
|
||
#include "yuv4mpeg.h"
|
||
#include "yuv4mpeg_intern.h"
|
||
|
||
static y4m_ratio_t mpeg_framerates[] = {
|
||
Y4M_FPS_UNKNOWN,
|
||
Y4M_FPS_NTSC_FILM,
|
||
Y4M_FPS_FILM,
|
||
Y4M_FPS_PAL,
|
||
Y4M_FPS_NTSC,
|
||
Y4M_FPS_30,
|
||
Y4M_FPS_PAL_FIELD,
|
||
Y4M_FPS_NTSC_FIELD,
|
||
Y4M_FPS_60
|
||
};
|
||
|
||
|
||
#define MPEG_NUM_RATES (sizeof(mpeg_framerates)/sizeof(mpeg_framerates[0]))
|
||
const mpeg_framerate_code_t mpeg_num_framerates = MPEG_NUM_RATES;
|
||
|
||
static const char *framerate_definitions[MPEG_NUM_RATES] = {
|
||
"illegal",
|
||
"24000.0/1001.0 (NTSC 3:2 pulldown converted FILM)",
|
||
"24.0 (NATIVE FILM)",
|
||
"25.0 (PAL/SECAM VIDEO / converted FILM)",
|
||
"30000.0/1001.0 (NTSC VIDEO)",
|
||
"30.0",
|
||
"50.0 (PAL FIELD RATE)",
|
||
"60000.0/1001.0 (NTSC FIELD RATE)",
|
||
"60.0"
|
||
};
|
||
|
||
|
||
static const char *mpeg1_aspect_ratio_definitions[] = {
|
||
"1:1 (square pixels)",
|
||
"1:0.6735",
|
||
"1:0.7031 (16:9 Anamorphic PAL/SECAM for 720x578/352x288 images)",
|
||
"1:0.7615",
|
||
"1:0.8055",
|
||
"1:0.8437 (16:9 Anamorphic NTSC for 720x480/352x240 images)",
|
||
"1:0.8935",
|
||
"1:0.9375 (4:3 PAL/SECAM for 720x578/352x288 images)",
|
||
"1:0.9815",
|
||
"1:1.0255",
|
||
"1:1:0695",
|
||
"1:1.1250 (4:3 NTSC for 720x480/352x240 images)",
|
||
"1:1.1575",
|
||
"1:1.2015"
|
||
};
|
||
|
||
static const y4m_ratio_t mpeg1_aspect_ratios[] = {
|
||
Y4M_SAR_MPEG1_1,
|
||
Y4M_SAR_MPEG1_2,
|
||
Y4M_SAR_MPEG1_3, /* Anamorphic 16:9 PAL */
|
||
Y4M_SAR_MPEG1_4,
|
||
Y4M_SAR_MPEG1_5,
|
||
Y4M_SAR_MPEG1_6, /* Anamorphic 16:9 NTSC */
|
||
Y4M_SAR_MPEG1_7,
|
||
Y4M_SAR_MPEG1_8, /* PAL/SECAM 4:3 */
|
||
Y4M_SAR_MPEG1_9,
|
||
Y4M_SAR_MPEG1_10,
|
||
Y4M_SAR_MPEG1_11,
|
||
Y4M_SAR_MPEG1_12, /* NTSC 4:3 */
|
||
Y4M_SAR_MPEG1_13,
|
||
Y4M_SAR_MPEG1_14,
|
||
};
|
||
|
||
static const char *mpeg2_aspect_ratio_definitions[] = {
|
||
"1:1 pixels",
|
||
"4:3 display",
|
||
"16:9 display",
|
||
"2.21:1 display"
|
||
};
|
||
|
||
|
||
static const y4m_ratio_t mpeg2_aspect_ratios[] = {
|
||
Y4M_DAR_MPEG2_1,
|
||
Y4M_DAR_MPEG2_2,
|
||
Y4M_DAR_MPEG2_3,
|
||
Y4M_DAR_MPEG2_4
|
||
};
|
||
|
||
static const char **aspect_ratio_definitions[2] = {
|
||
mpeg1_aspect_ratio_definitions,
|
||
mpeg2_aspect_ratio_definitions
|
||
};
|
||
|
||
static const y4m_ratio_t *mpeg_aspect_ratios[2] = {
|
||
mpeg1_aspect_ratios,
|
||
mpeg2_aspect_ratios
|
||
};
|
||
|
||
const mpeg_aspect_code_t mpeg_num_aspect_ratios[2] = {
|
||
sizeof (mpeg1_aspect_ratios) / sizeof (mpeg1_aspect_ratios[0]),
|
||
sizeof (mpeg2_aspect_ratios) / sizeof (mpeg2_aspect_ratios[0])
|
||
};
|
||
|
||
/*
|
||
* Convert MPEG frame-rate code to corresponding frame-rate
|
||
*/
|
||
|
||
y4m_ratio_t
|
||
mpeg_framerate (mpeg_framerate_code_t code)
|
||
{
|
||
if (code == 0 || code > mpeg_num_framerates)
|
||
return y4m_fps_UNKNOWN;
|
||
else
|
||
return mpeg_framerates[code];
|
||
}
|
||
|
||
/*
|
||
* Look-up MPEG frame rate code for a (exact) frame rate.
|
||
*/
|
||
|
||
|
||
mpeg_framerate_code_t
|
||
mpeg_framerate_code (y4m_ratio_t framerate)
|
||
{
|
||
mpeg_framerate_code_t i;
|
||
|
||
y4m_ratio_reduce (&framerate);
|
||
for (i = 1; i < mpeg_num_framerates; ++i) {
|
||
if (Y4M_RATIO_EQL (framerate, mpeg_framerates[i]))
|
||
return i;
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
|
||
/* small enough to distinguish 1/1000 from 1/1001 */
|
||
#define MPEG_FPS_TOLERANCE 0.0001
|
||
|
||
|
||
y4m_ratio_t
|
||
mpeg_conform_framerate (double fps)
|
||
{
|
||
mpeg_framerate_code_t i;
|
||
y4m_ratio_t result;
|
||
|
||
/* try to match it to a standard frame rate */
|
||
for (i = 1; i < mpeg_num_framerates; i++) {
|
||
double deviation = 1.0 - (Y4M_RATIO_DBL (mpeg_framerates[i]) / fps);
|
||
|
||
if ((deviation > -MPEG_FPS_TOLERANCE) && (deviation < +MPEG_FPS_TOLERANCE))
|
||
return mpeg_framerates[i];
|
||
}
|
||
/* no luck? just turn it into a ratio (6 decimal place accuracy) */
|
||
result.n = (int) ((fps * 1000000.0) + 0.5);
|
||
result.d = 1000000;
|
||
y4m_ratio_reduce (&result);
|
||
return result;
|
||
}
|
||
|
||
|
||
|
||
/*
|
||
* Convert MPEG aspect-ratio code to corresponding aspect-ratio
|
||
*/
|
||
|
||
y4m_ratio_t
|
||
mpeg_aspect_ratio (int mpeg_version, mpeg_aspect_code_t code)
|
||
{
|
||
y4m_ratio_t ratio;
|
||
|
||
if (mpeg_version < 1 || mpeg_version > 2)
|
||
return y4m_sar_UNKNOWN;
|
||
if (code == 0 || code > mpeg_num_aspect_ratios[mpeg_version - 1])
|
||
return y4m_sar_UNKNOWN;
|
||
else {
|
||
ratio = mpeg_aspect_ratios[mpeg_version - 1][code - 1];
|
||
y4m_ratio_reduce (&ratio);
|
||
return ratio;
|
||
}
|
||
}
|
||
|
||
/*
|
||
* Look-up corresponding MPEG aspect ratio code given an exact 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.
|
||
*
|
||
*/
|
||
|
||
mpeg_aspect_code_t
|
||
mpeg_frame_aspect_code (int mpeg_version, y4m_ratio_t aspect_ratio)
|
||
{
|
||
mpeg_aspect_code_t i;
|
||
y4m_ratio_t red_ratio = aspect_ratio;
|
||
|
||
y4m_ratio_reduce (&red_ratio);
|
||
if (mpeg_version < 1 || mpeg_version > 2)
|
||
return 0;
|
||
for (i = 1; i < mpeg_num_aspect_ratios[mpeg_version - 1]; ++i) {
|
||
y4m_ratio_t red_entry = mpeg_aspect_ratios[mpeg_version - 1][i - 1];
|
||
|
||
y4m_ratio_reduce (&red_entry);
|
||
if (Y4M_RATIO_EQL (red_entry, red_ratio))
|
||
return i;
|
||
}
|
||
|
||
return 0;
|
||
|
||
}
|
||
|
||
|
||
|
||
/*
|
||
* 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 guess.
|
||
*
|
||
*/
|
||
|
||
|
||
/* this is big enough to accommodate the difference between 720 and 704 */
|
||
#define GUESS_ASPECT_TOLERANCE 0.03
|
||
|
||
mpeg_aspect_code_t
|
||
mpeg_guess_mpeg_aspect_code (int mpeg_version, y4m_ratio_t sampleaspect,
|
||
int frame_width, int frame_height)
|
||
{
|
||
if (Y4M_RATIO_EQL (sampleaspect, y4m_sar_UNKNOWN)) {
|
||
return 0;
|
||
}
|
||
switch (mpeg_version) {
|
||
case 1:
|
||
if (Y4M_RATIO_EQL (sampleaspect, y4m_sar_SQUARE)) {
|
||
return 1;
|
||
} else if (Y4M_RATIO_EQL (sampleaspect, y4m_sar_NTSC_CCIR601)) {
|
||
return 12;
|
||
} else if (Y4M_RATIO_EQL (sampleaspect, y4m_sar_NTSC_16_9)) {
|
||
return 6;
|
||
} else if (Y4M_RATIO_EQL (sampleaspect, y4m_sar_PAL_CCIR601)) {
|
||
return 8;
|
||
} else if (Y4M_RATIO_EQL (sampleaspect, y4m_sar_PAL_16_9)) {
|
||
return 3;
|
||
}
|
||
return 0;
|
||
break;
|
||
case 2:
|
||
if (Y4M_RATIO_EQL (sampleaspect, y4m_sar_SQUARE)) {
|
||
return 1; /* '1' means square *pixels* in MPEG-2; go figure. */
|
||
} else {
|
||
unsigned int i;
|
||
double true_far; /* true frame aspect ratio */
|
||
|
||
true_far =
|
||
(double) (sampleaspect.n * frame_width) / (double) (sampleaspect.d * frame_height);
|
||
/* start at '2'... */
|
||
for (i = 2; i < mpeg_num_aspect_ratios[mpeg_version - 1]; i++) {
|
||
double ratio = true_far / Y4M_RATIO_DBL (mpeg_aspect_ratios[mpeg_version - 1][i - 1]);
|
||
|
||
if ((ratio > (1.0 - GUESS_ASPECT_TOLERANCE)) && (ratio < (1.0 + GUESS_ASPECT_TOLERANCE)))
|
||
return i;
|
||
}
|
||
return 0;
|
||
}
|
||
break;
|
||
default:
|
||
return 0;
|
||
break;
|
||
}
|
||
}
|
||
|
||
|
||
|
||
|
||
/*
|
||
* 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 guess.
|
||
*
|
||
*/
|
||
y4m_ratio_t
|
||
mpeg_guess_sample_aspect_ratio (int mpeg_version,
|
||
mpeg_aspect_code_t code, int frame_width, int frame_height)
|
||
{
|
||
switch (mpeg_version) {
|
||
case 1:
|
||
/* MPEG-1 codes turn into SAR's, just not quite the right ones.
|
||
For the common/known values, we provide the ratio used in practice,
|
||
otherwise say we don't know. */
|
||
switch (code) {
|
||
case 1:
|
||
return y4m_sar_SQUARE;
|
||
break;
|
||
case 3:
|
||
return y4m_sar_PAL_16_9;
|
||
break;
|
||
case 6:
|
||
return y4m_sar_NTSC_16_9;
|
||
break;
|
||
case 8:
|
||
return y4m_sar_PAL_CCIR601;
|
||
break;
|
||
case 12:
|
||
return y4m_sar_NTSC_CCIR601;
|
||
break;
|
||
default:
|
||
return y4m_sar_UNKNOWN;
|
||
break;
|
||
}
|
||
break;
|
||
case 2:
|
||
/* MPEG-2 codes turn into Frame Aspect Ratios, though not exactly the
|
||
FAR's used in practice. For common/standard frame sizes, we provide
|
||
the original SAR; otherwise, we say we don't know. */
|
||
if (code == 1) {
|
||
return y4m_sar_SQUARE; /* '1' means square *pixels* in MPEG-2 */
|
||
} else if ((code >= 2) && (code <= 4)) {
|
||
return y4m_guess_sar (frame_width, frame_height, mpeg2_aspect_ratios[code - 1]);
|
||
} else {
|
||
return y4m_sar_UNKNOWN;
|
||
}
|
||
break;
|
||
default:
|
||
return y4m_sar_UNKNOWN;
|
||
break;
|
||
}
|
||
}
|
||
|
||
|
||
|
||
|
||
|
||
/*
|
||
* Look-up MPEG explanatory definition string for frame rate code
|
||
*
|
||
*/
|
||
|
||
|
||
const char *
|
||
mpeg_framerate_code_definition (mpeg_framerate_code_t code)
|
||
{
|
||
if (code == 0 || code >= mpeg_num_framerates)
|
||
return "UNDEFINED: illegal/reserved frame-rate ratio code";
|
||
|
||
return framerate_definitions[code];
|
||
}
|
||
|
||
/*
|
||
* 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)
|
||
{
|
||
if (mpeg_version < 1 || mpeg_version > 2)
|
||
return "UNDEFINED: illegal MPEG version";
|
||
|
||
if (code < 1 || code > mpeg_num_aspect_ratios[mpeg_version - 1])
|
||
return "UNDEFINED: illegal aspect ratio code";
|
||
|
||
return aspect_ratio_definitions[mpeg_version - 1][code - 1];
|
||
}
|
||
|
||
|
||
/*
|
||
* Look-up explanatory definition of interlace field order code
|
||
*
|
||
*/
|
||
|
||
const char *
|
||
mpeg_interlace_code_definition (int yuv4m_interlace_code)
|
||
{
|
||
const char *def;
|
||
|
||
switch (yuv4m_interlace_code) {
|
||
case Y4M_UNKNOWN:
|
||
def = "unknown";
|
||
break;
|
||
case Y4M_ILACE_NONE:
|
||
def = "none/progressive";
|
||
break;
|
||
case Y4M_ILACE_TOP_FIRST:
|
||
def = "top-field-first";
|
||
break;
|
||
case Y4M_ILACE_BOTTOM_FIRST:
|
||
def = "bottom-field-first";
|
||
break;
|
||
default:
|
||
def = "UNDEFINED: illegal video interlacing type-code!";
|
||
break;
|
||
}
|
||
return def;
|
||
}
|
||
|
||
|
||
/*
|
||
* Local variables:
|
||
* c-file-style: "stroustrup"
|
||
* tab-width: 4
|
||
* indent-tabs-mode: nil
|
||
* End:
|
||
*/
|