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mpv/demux/mpeg_hdr.c

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/*
* based on libmpeg2/header.c by Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
*
* This file is part of MPlayer.
*
* MPlayer is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* MPlayer 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 MPlayer; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "config.h"
#include "mpeg_hdr.h"
#include "libavutil/attributes.h"
#include "core/mp_msg.h"
static float frameratecode2framerate[16] = {
0,
// Official mpeg1/2 framerates: (1-8)
24000.0/1001, 24,25,
30000.0/1001, 30,50,
60000.0/1001, 60,
// Xing's 15fps: (9)
15,
// libmpeg3's "Unofficial economy rates": (10-13)
5,10,12,15,
// some invalid ones: (14-15)
0,0
};
int mp_header_process_sequence_header (mp_mpeg_header_t * picture, const unsigned char * buffer)
{
int height;
if ((buffer[6] & 0x20) != 0x20){
fprintf(stderr, "missing marker bit!\n");
return 1; /* missing marker_bit */
}
height = (buffer[0] << 16) | (buffer[1] << 8) | buffer[2];
picture->display_picture_width = height >> 12;
picture->display_picture_height = height & 0xfff;
picture->aspect_ratio_information = buffer[3] >> 4;
picture->frame_rate_code = buffer[3] & 15;
picture->fps=frameratecode2framerate[picture->frame_rate_code];
picture->bitrate = (buffer[4]<<10)|(buffer[5]<<2)|(buffer[6]>>6);
picture->mpeg1 = 1;
picture->picture_structure = 3; //FRAME_PICTURE;
picture->display_time=100;
picture->frame_rate_extension_n = 1;
picture->frame_rate_extension_d = 1;
return 0;
}
static int header_process_sequence_extension (mp_mpeg_header_t * picture,
unsigned char * buffer)
{
/* check chroma format, size extensions, marker bit */
if ( ((buffer[1] & 0x06) == 0x00) ||
((buffer[1] & 0x01) != 0x00) || (buffer[2] & 0xe0) ||
((buffer[3] & 0x01) != 0x01) )
return 1;
picture->progressive_sequence = (buffer[1] >> 3) & 1;
picture->frame_rate_extension_n = ((buffer[5] >> 5) & 3) + 1;
picture->frame_rate_extension_d = (buffer[5] & 0x1f) + 1;
picture->mpeg1 = 0;
return 0;
}
static int header_process_picture_coding_extension (mp_mpeg_header_t * picture, unsigned char * buffer)
{
picture->picture_structure = buffer[2] & 3;
picture->top_field_first = buffer[3] >> 7;
picture->repeat_first_field = (buffer[3] >> 1) & 1;
picture->progressive_frame = buffer[4] >> 7;
// repeat_first implementation by A'rpi/ESP-team, based on libmpeg3:
picture->display_time=100;
if(picture->repeat_first_field){
if(picture->progressive_sequence){
if(picture->top_field_first)
picture->display_time+=200;
else
picture->display_time+=100;
} else
if(picture->progressive_frame){
picture->display_time+=50;
}
}
//temopral hack. We calc time on every field, so if we have 2 fields
// interlaced we'll end with double time for 1 frame
if( picture->picture_structure!=3 ) picture->display_time/=2;
return 0;
}
int mp_header_process_extension (mp_mpeg_header_t * picture, unsigned char * buffer)
{
switch (buffer[0] & 0xf0) {
case 0x10: /* sequence extension */
return header_process_sequence_extension (picture, buffer);
case 0x80: /* picture coding extension */
return header_process_picture_coding_extension (picture, buffer);
}
return 0;
}
float mpeg12_aspect_info(mp_mpeg_header_t *picture)
{
float aspect = 0.0;
switch(picture->aspect_ratio_information) {
case 2: // PAL/NTSC SVCD/DVD 4:3
case 8: // PAL VCD 4:3
case 12: // NTSC VCD 4:3
aspect=4.0/3.0;
break;
case 3: // PAL/NTSC Widescreen SVCD/DVD 16:9
case 6: // (PAL?)/NTSC Widescreen SVCD 16:9
aspect=16.0/9.0;
break;
case 4: // according to ISO-138182-2 Table 6.3
aspect=2.21;
break;
case 1: // VGA 1:1 - do not prescale
case 9: // Movie Type ??? / 640x480
aspect=0.0;
break;
default:
mp_msg(MSGT_DECVIDEO,MSGL_ERR,"Detected unknown aspect_ratio_information in mpeg sequence header.\n"
"Please report the aspect value (%i) along with the movie type (VGA,PAL,NTSC,"
"SECAM) and the movie resolution (720x576,352x240,480x480,...) to the MPlayer"
" developers, so that we can add support for it!\nAssuming 1:1 aspect for now.\n",
picture->aspect_ratio_information);
}
return aspect;
}
//MPEG4 HEADERS
unsigned char mp_getbits(unsigned char *buffer, unsigned int from, unsigned char len)
{
unsigned int n;
unsigned char m, u, l, y;
n = from / 8;
m = from % 8;
u = 8 - m;
l = (len > u ? len - u : 0);
y = (buffer[n] << m);
if(8 > len)
y >>= (8-len);
if(l)
y |= (buffer[n+1] >> (8-l));
//fprintf(stderr, "GETBITS(%d -> %d): bytes=0x%x 0x%x, n=%d, m=%d, l=%d, u=%d, Y=%d\n",
// from, (int) len, (int) buffer[n],(int) buffer[n+1], n, (int) m, (int) l, (int) u, (int) y);
return y;
}
static inline unsigned int mp_getbits16(unsigned char *buffer, unsigned int from, unsigned char len)
{
if(len > 8)
return (mp_getbits(buffer, from, len - 8) << 8) | mp_getbits(buffer, from + len - 8, 8);
else
return mp_getbits(buffer, from, len);
}
#define getbits mp_getbits
#define getbits16 mp_getbits16
static int read_timeinc(mp_mpeg_header_t * picture, unsigned char * buffer, int n)
{
if(picture->timeinc_bits > 8) {
picture->timeinc_unit = getbits(buffer, n, picture->timeinc_bits - 8) << 8;
n += picture->timeinc_bits - 8;
picture->timeinc_unit |= getbits(buffer, n, 8);
n += 8;
} else {
picture->timeinc_unit = getbits(buffer, n, picture->timeinc_bits);
n += picture->timeinc_bits;
}
//fprintf(stderr, "TIMEINC2: %d, bits: %d\n", picture->timeinc_unit, picture->timeinc_bits);
return n;
}
int mp4_header_process_vol(mp_mpeg_header_t * picture, unsigned char * buffer)
{
unsigned int n, aspect=0, aspectw av_unused=0, aspecth av_unused=0, x=1, v;
//begins with 0x0000012x
picture->fps = 0;
picture->timeinc_bits = picture->timeinc_resolution = picture->timeinc_unit = 0;
n = 9;
if(getbits(buffer, n, 1))
n += 7;
n++;
aspect=getbits(buffer, n, 4);
n += 4;
if(aspect == 0x0f) {
aspectw = getbits(buffer, n, 8);
n += 8;
aspecth = getbits(buffer, n, 8);
n += 8;
}
if(getbits(buffer, n, 1)) {
n += 4;
if(getbits(buffer, n, 1))
n += 79;
n++;
} else n++;
n+=3;
picture->timeinc_resolution = getbits(buffer, n, 8) << 8;
n += 8;
picture->timeinc_resolution |= getbits(buffer, n, 8);
n += 8;
picture->timeinc_bits = 0;
v = picture->timeinc_resolution - 1;
while(v && (x<16)) {
v>>=1;
picture->timeinc_bits++;
}
picture->timeinc_bits = (picture->timeinc_bits > 1 ? picture->timeinc_bits : 1);
n++; //marker bit
if(getbits(buffer, n++, 1)) { //fixed_vop_timeinc
n += read_timeinc(picture, buffer, n);
if(picture->timeinc_unit)
picture->fps = (float) picture->timeinc_resolution / (float) picture->timeinc_unit;
}
n++; //marker bit
picture->display_picture_width = getbits16(buffer, n, 13);
n += 13;
n++; //marker bit
picture->display_picture_height = getbits16(buffer, n, 13);
n += 13;
//fprintf(stderr, "ASPECT: %d, PARW=%d, PARH=%d, TIMEINCRESOLUTION: %d, FIXED_TIMEINC: %d (number of bits: %d), FPS: %u\n",
// aspect, aspectw, aspecth, picture->timeinc_resolution, picture->timeinc_unit, picture->timeinc_bits, picture->fps);
return 0;
}
void mp4_header_process_vop(mp_mpeg_header_t * picture, unsigned char * buffer)
{
int n;
n = 0;
picture->picture_type = getbits(buffer, n, 2);
n += 2;
while(getbits(buffer, n, 1))
n++;
n++;
getbits(buffer, n, 1);
n++;
n += read_timeinc(picture, buffer, n);
}
#define min(a, b) ((a) <= (b) ? (a) : (b))
static unsigned int read_golomb(unsigned char *buffer, unsigned int *init)
{
unsigned int x, v = 0, v2 = 0, m, len = 0, n = *init;
while(getbits(buffer, n++, 1) == 0)
len++;
x = len + n;
while(n < x)
{
m = min(x - n, 8);
v |= getbits(buffer, n, m);
n += m;
if(x - n > 8)
v <<= 8;
}
v2 = 1;
for(n = 0; n < len; n++)
v2 <<= 1;
v2 = (v2 - 1) + v;
//fprintf(stderr, "READ_GOLOMB(%u), V=2^%u + %u-1 = %u\n", *init, len, v, v2);
*init = x;
return v2;
}
inline static int read_golomb_s(unsigned char *buffer, unsigned int *init)
{
unsigned int v = read_golomb(buffer, init);
return (v & 1) ? ((v + 1) >> 1) : -(v >> 1);
}
static int h264_parse_vui(mp_mpeg_header_t * picture, unsigned char * buf, unsigned int n)
{
unsigned int overscan, vsp_color, chroma, timing, fixed_fps;
if(getbits(buf, n++, 1))
{
picture->aspect_ratio_information = getbits(buf, n, 8);
n += 8;
if(picture->aspect_ratio_information == 255)
{
picture->display_picture_width = (getbits(buf, n, 8) << 8) | getbits(buf, n + 8, 8);
n += 16;
picture->display_picture_height = (getbits(buf, n, 8) << 8) | getbits(buf, n + 8, 8);
n += 16;
}
}
if((overscan=getbits(buf, n++, 1)))
n++;
if((vsp_color=getbits(buf, n++, 1)))
{
n += 4;
if(getbits(buf, n++, 1))
n += 24;
}
if((chroma=getbits(buf, n++, 1)))
{
read_golomb(buf, &n);
read_golomb(buf, &n);
}
if((timing=getbits(buf, n++, 1)))
{
picture->timeinc_unit = (getbits(buf, n, 8) << 24) | (getbits(buf, n+8, 8) << 16) | (getbits(buf, n+16, 8) << 8) | getbits(buf, n+24, 8);
n += 32;
picture->timeinc_resolution = (getbits(buf, n, 8) << 24) | (getbits(buf, n+8, 8) << 16) | (getbits(buf, n+16, 8) << 8) | getbits(buf, n+24, 8);
n += 32;
fixed_fps = getbits(buf, n, 1);
if(picture->timeinc_unit > 0 && picture->timeinc_resolution > 0)
picture->fps = (float) picture->timeinc_resolution / (float) picture->timeinc_unit;
if(fixed_fps)
picture->fps /= 2;
}
//fprintf(stderr, "H264_PARSE_VUI, OVESCAN=%u, VSP_COLOR=%u, CHROMA=%u, TIMING=%u, DISPW=%u, DISPH=%u, TIMERES=%u, TIMEINC=%u, FIXED_FPS=%u\n", overscan, vsp_color, chroma, timing, picture->display_picture_width, picture->display_picture_height,
// picture->timeinc_resolution, picture->timeinc_unit, picture->timeinc_unit, fixed_fps);
return n;
}
static int mp_unescape03(unsigned char *buf, int len)
{
unsigned char *dest;
int i, j, skip;
dest = malloc(len);
if(! dest)
return 0;
j = i = skip = 0;
while(i <= len-3)
{
if(buf[i] == 0 && buf[i+1] == 0 && buf[i+2] == 3)
{
dest[j] = dest[j+1] = 0;
j += 2;
i += 3;
skip++;
}
else
{
dest[j] = buf[i];
j++;
i++;
}
}
dest[j] = buf[len-2];
dest[j+1] = buf[len-1];
len -= skip;
memcpy(buf, dest, len);
free(dest);
return len;
}
int h264_parse_sps(mp_mpeg_header_t * picture, unsigned char * buf, int len)
{
unsigned int n = 0, v, i, k, mbh;
int frame_mbs_only;
len = mp_unescape03(buf, len);
picture->fps = picture->timeinc_unit = picture->timeinc_resolution = 0;
n = 24;
read_golomb(buf, &n);
if(buf[0] >= 100){
if(read_golomb(buf, &n) == 3)
n++;
read_golomb(buf, &n);
read_golomb(buf, &n);
n++;
if(getbits(buf, n++, 1)){
for(i = 0; i < 8; i++)
{ // scaling list is skipped for now
if(getbits(buf, n++, 1))
{
v = 8;
for(k = (i < 6 ? 16 : 64); k && v; k--)
v = (v + read_golomb_s(buf, &n)) & 255;
}
}
}
}
read_golomb(buf, &n);
v = read_golomb(buf, &n);
if(v == 0)
read_golomb(buf, &n);
else if(v == 1)
{
getbits(buf, n++, 1);
read_golomb(buf, &n);
read_golomb(buf, &n);
v = read_golomb(buf, &n);
for(i = 0; i < v; i++)
read_golomb(buf, &n);
}
read_golomb(buf, &n);
getbits(buf, n++, 1);
picture->display_picture_width = 16 *(read_golomb(buf, &n)+1);
mbh = read_golomb(buf, &n)+1;
frame_mbs_only = getbits(buf, n++, 1);
picture->display_picture_height = 16 * (2 - frame_mbs_only) * mbh;
if(!frame_mbs_only)
getbits(buf, n++, 1);
getbits(buf, n++, 1);
if(getbits(buf, n++, 1))
{
read_golomb(buf, &n);
read_golomb(buf, &n);
read_golomb(buf, &n);
read_golomb(buf, &n);
}
if(getbits(buf, n++, 1))
n = h264_parse_vui(picture, buf, n);
return n;
}
int mp_vc1_decode_sequence_header(mp_mpeg_header_t * picture, unsigned char * buf, int len)
{
int n, x;
len = mp_unescape03(buf, len);
picture->display_picture_width = picture->display_picture_height = 0;
picture->fps = 0;
n = 0;
x = getbits(buf, n, 2);
n += 2;
if(x != 3) //not advanced profile
return 0;
getbits16(buf, n, 14);
n += 14;
picture->display_picture_width = getbits16(buf, n, 12) * 2 + 2;
n += 12;
picture->display_picture_height = getbits16(buf, n, 12) * 2 + 2;
n += 12;
getbits(buf, n, 6);
n += 6;
x = getbits(buf, n, 1);
n += 1;
if(x) //display info
{
getbits16(buf, n, 14);
n += 14;
getbits16(buf, n, 14);
n += 14;
if(getbits(buf, n++, 1)) //aspect ratio
{
x = getbits(buf, n, 4);
n += 4;
if(x == 15)
{
getbits16(buf, n, 16);
n += 16;
}
}
if(getbits(buf, n++, 1)) //framerates
{
int frexp=0, frnum=0, frden=0;
if(getbits(buf, n++, 1))
{
frexp = getbits16(buf, n, 16);
n += 16;
picture->fps = (double) (frexp+1) / 32.0;
}
else
{
float frates[] = {0, 24000, 25000, 30000, 50000, 60000, 48000, 72000, 0};
float frdivs[] = {0, 1000, 1001, 0};
frnum = getbits(buf, n, 8);
n += 8;
frden = getbits(buf, n, 4);
n += 4;
if((frden == 1 || frden == 2) && (frnum < 8))
picture->fps = frates[frnum] / frdivs[frden];
}
}
}
//free(dest);
return 1;
}
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