mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-02 03:06:28 +02:00
50e2450bc1
DVB subtitle decoder by (Ian Caulfield: imc25, cam ac uk) Originally committed as revision 4449 to svn://svn.ffmpeg.org/ffmpeg/trunk
470 lines
14 KiB
C
470 lines
14 KiB
C
/*
|
|
* DVD subtitle decoding for ffmpeg
|
|
* Copyright (c) 2005 Fabrice Bellard.
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2 of the License, or (at your option) any later version.
|
|
*
|
|
* This library 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
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with this library; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
#include "avcodec.h"
|
|
|
|
//#define DEBUG
|
|
|
|
typedef struct DVDSubContext {
|
|
} DVDSubContext;
|
|
|
|
static int dvdsub_init_decoder(AVCodecContext *avctx)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
uint16_t getbe16(const uint8_t *p)
|
|
{
|
|
return (p[0] << 8) | p[1];
|
|
}
|
|
|
|
int get_nibble(const uint8_t *buf, int nibble_offset)
|
|
{
|
|
return (buf[nibble_offset >> 1] >> ((1 - (nibble_offset & 1)) << 2)) & 0xf;
|
|
}
|
|
|
|
static int decode_rle(uint8_t *bitmap, int linesize, int w, int h,
|
|
const uint8_t *buf, int nibble_offset, int buf_size)
|
|
{
|
|
unsigned int v;
|
|
int x, y, len, color, nibble_end;
|
|
uint8_t *d;
|
|
|
|
nibble_end = buf_size * 2;
|
|
x = 0;
|
|
y = 0;
|
|
d = bitmap;
|
|
for(;;) {
|
|
if (nibble_offset >= nibble_end)
|
|
return -1;
|
|
v = get_nibble(buf, nibble_offset++);
|
|
if (v < 0x4) {
|
|
v = (v << 4) | get_nibble(buf, nibble_offset++);
|
|
if (v < 0x10) {
|
|
v = (v << 4) | get_nibble(buf, nibble_offset++);
|
|
if (v < 0x040) {
|
|
v = (v << 4) | get_nibble(buf, nibble_offset++);
|
|
if (v < 4) {
|
|
v |= (w - x) << 2;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
len = v >> 2;
|
|
if (len > (w - x))
|
|
len = (w - x);
|
|
color = v & 0x03;
|
|
memset(d + x, color, len);
|
|
x += len;
|
|
if (x >= w) {
|
|
y++;
|
|
if (y >= h)
|
|
break;
|
|
d += linesize;
|
|
x = 0;
|
|
/* byte align */
|
|
nibble_offset += (nibble_offset & 1);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void guess_palette(uint32_t *rgba_palette,
|
|
uint8_t *palette,
|
|
uint8_t *alpha,
|
|
uint32_t subtitle_color)
|
|
{
|
|
uint8_t color_used[16];
|
|
int nb_opaque_colors, i, level, j, r, g, b;
|
|
|
|
for(i = 0; i < 4; i++)
|
|
rgba_palette[i] = 0;
|
|
|
|
memset(color_used, 0, 16);
|
|
nb_opaque_colors = 0;
|
|
for(i = 0; i < 4; i++) {
|
|
if (alpha[i] != 0 && !color_used[palette[i]]) {
|
|
color_used[palette[i]] = 1;
|
|
nb_opaque_colors++;
|
|
}
|
|
}
|
|
|
|
if (nb_opaque_colors == 0)
|
|
return;
|
|
|
|
j = 0;
|
|
memset(color_used, 0, 16);
|
|
for(i = 0; i < 4; i++) {
|
|
if (alpha[i] != 0) {
|
|
if (!color_used[palette[i]]) {
|
|
level = (0xff * (j + 1)) / nb_opaque_colors;
|
|
r = (((subtitle_color >> 16) & 0xff) * level) >> 8;
|
|
g = (((subtitle_color >> 8) & 0xff) * level) >> 8;
|
|
b = (((subtitle_color >> 0) & 0xff) * level) >> 8;
|
|
rgba_palette[i] = b | (g << 8) | (r << 16) | (0xff << 24);
|
|
color_used[palette[i]] = (i + 1);
|
|
j++;
|
|
} else {
|
|
rgba_palette[i] = rgba_palette[color_used[palette[i]] - 1];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static int decode_dvd_subtitles(AVSubtitle *sub_header,
|
|
const uint8_t *buf, int buf_size)
|
|
{
|
|
int cmd_pos, pos, cmd, x1, y1, x2, y2, offset1, offset2, next_cmd_pos;
|
|
uint8_t palette[4], alpha[4];
|
|
int date;
|
|
int i;
|
|
|
|
if (buf_size < 4)
|
|
return -1;
|
|
sub_header->rects = NULL;
|
|
sub_header->num_rects = 0;
|
|
sub_header->start_display_time = 0;
|
|
sub_header->end_display_time = 0;
|
|
|
|
cmd_pos = getbe16(buf + 2);
|
|
while ((cmd_pos + 4) < buf_size) {
|
|
date = getbe16(buf + cmd_pos);
|
|
next_cmd_pos = getbe16(buf + cmd_pos + 2);
|
|
#ifdef DEBUG
|
|
av_log(NULL, AV_LOG_INFO, "cmd_pos=0x%04x next=0x%04x date=%d\n",
|
|
cmd_pos, next_cmd_pos, date);
|
|
#endif
|
|
pos = cmd_pos + 4;
|
|
offset1 = -1;
|
|
offset2 = -1;
|
|
x1 = y1 = x2 = y2 = 0;
|
|
while (pos < buf_size) {
|
|
cmd = buf[pos++];
|
|
#ifdef DEBUG
|
|
av_log(NULL, AV_LOG_INFO, "cmd=%02x\n", cmd);
|
|
#endif
|
|
switch(cmd) {
|
|
case 0x00:
|
|
/* force display */
|
|
break;
|
|
case 0x01:
|
|
/* set start date */
|
|
sub_header->start_display_time = date * 10;
|
|
break;
|
|
case 0x02:
|
|
/* set end date */
|
|
sub_header->end_display_time = date * 10;
|
|
break;
|
|
case 0x03:
|
|
/* set palette */
|
|
if ((buf_size - pos) < 2)
|
|
goto fail;
|
|
palette[0] = buf[pos] >> 4;
|
|
palette[1] = buf[pos] & 0x0f;
|
|
palette[2] = buf[pos + 1] >> 4;
|
|
palette[3] = buf[pos + 1] & 0x0f;
|
|
pos += 2;
|
|
break;
|
|
case 0x04:
|
|
/* set alpha */
|
|
if ((buf_size - pos) < 2)
|
|
goto fail;
|
|
alpha[0] = buf[pos] >> 4;
|
|
alpha[1] = buf[pos] & 0x0f;
|
|
alpha[2] = buf[pos + 1] >> 4;
|
|
alpha[3] = buf[pos + 1] & 0x0f;
|
|
pos += 2;
|
|
break;
|
|
case 0x05:
|
|
if ((buf_size - pos) < 6)
|
|
goto fail;
|
|
x1 = (buf[pos] << 4) | (buf[pos + 1] >> 4);
|
|
x2 = ((buf[pos + 1] & 0x0f) << 8) | buf[pos + 2];
|
|
y1 = (buf[pos + 3] << 4) | (buf[pos + 4] >> 4);
|
|
y2 = ((buf[pos + 4] & 0x0f) << 8) | buf[pos + 5];
|
|
#ifdef DEBUG
|
|
av_log(NULL, AV_LOG_INFO, "x1=%d x2=%d y1=%d y2=%d\n",
|
|
x1, x2, y1, y2);
|
|
#endif
|
|
pos += 6;
|
|
break;
|
|
case 0x06:
|
|
if ((buf_size - pos) < 4)
|
|
goto fail;
|
|
offset1 = getbe16(buf + pos);
|
|
offset2 = getbe16(buf + pos + 2);
|
|
#ifdef DEBUG
|
|
av_log(NULL, AV_LOG_INFO, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2);
|
|
#endif
|
|
pos += 4;
|
|
break;
|
|
case 0xff:
|
|
default:
|
|
goto the_end;
|
|
}
|
|
}
|
|
the_end:
|
|
if (offset1 >= 0) {
|
|
int w, h;
|
|
uint8_t *bitmap;
|
|
|
|
/* decode the bitmap */
|
|
w = x2 - x1 + 1;
|
|
if (w < 0)
|
|
w = 0;
|
|
h = y2 - y1;
|
|
if (h < 0)
|
|
h = 0;
|
|
if (w > 0 && h > 0) {
|
|
if (sub_header->rects != NULL) {
|
|
for (i = 0; i < sub_header->num_rects; i++) {
|
|
av_free(sub_header->rects[i].bitmap);
|
|
av_free(sub_header->rects[i].rgba_palette);
|
|
}
|
|
av_freep(&sub_header->rects);
|
|
sub_header->num_rects = 0;
|
|
}
|
|
|
|
bitmap = av_malloc(w * h);
|
|
sub_header->rects = av_mallocz(sizeof(AVSubtitleRect));
|
|
sub_header->num_rects = 1;
|
|
sub_header->rects[0].rgba_palette = av_malloc(4 * 4);
|
|
decode_rle(bitmap, w * 2, w, h / 2,
|
|
buf, offset1 * 2, buf_size);
|
|
decode_rle(bitmap + w, w * 2, w, h / 2,
|
|
buf, offset2 * 2, buf_size);
|
|
guess_palette(sub_header->rects[0].rgba_palette,
|
|
palette, alpha, 0xffff00);
|
|
sub_header->rects[0].x = x1;
|
|
sub_header->rects[0].y = y1;
|
|
sub_header->rects[0].w = w;
|
|
sub_header->rects[0].h = h;
|
|
sub_header->rects[0].nb_colors = 4;
|
|
sub_header->rects[0].linesize = w;
|
|
sub_header->rects[0].bitmap = bitmap;
|
|
}
|
|
}
|
|
if (next_cmd_pos == cmd_pos)
|
|
break;
|
|
cmd_pos = next_cmd_pos;
|
|
}
|
|
if (sub_header->num_rects > 0)
|
|
return 0;
|
|
fail:
|
|
return -1;
|
|
}
|
|
|
|
static int is_transp(const uint8_t *buf, int pitch, int n,
|
|
const uint8_t *transp_color)
|
|
{
|
|
int i;
|
|
for(i = 0; i < n; i++) {
|
|
if (!transp_color[*buf])
|
|
return 0;
|
|
buf += pitch;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/* return 0 if empty rectangle, 1 if non empty */
|
|
static int find_smallest_bouding_rectangle(AVSubtitle *s)
|
|
{
|
|
uint8_t transp_color[256];
|
|
int y1, y2, x1, x2, y, w, h, i;
|
|
uint8_t *bitmap;
|
|
|
|
if (s->num_rects == 0 || s->rects == NULL || s->rects[0].w <= 0 || s->rects[0].h <= 0)
|
|
return 0;
|
|
|
|
memset(transp_color, 0, 256);
|
|
for(i = 0; i < s->rects[0].nb_colors; i++) {
|
|
if ((s->rects[0].rgba_palette[i] >> 24) == 0)
|
|
transp_color[i] = 1;
|
|
}
|
|
y1 = 0;
|
|
while (y1 < s->rects[0].h && is_transp(s->rects[0].bitmap + y1 * s->rects[0].linesize,
|
|
1, s->rects[0].w, transp_color))
|
|
y1++;
|
|
if (y1 == s->rects[0].h) {
|
|
av_freep(&s->rects[0].bitmap);
|
|
s->rects[0].w = s->rects[0].h = 0;
|
|
return 0;
|
|
}
|
|
|
|
y2 = s->rects[0].h - 1;
|
|
while (y2 > 0 && is_transp(s->rects[0].bitmap + y2 * s->rects[0].linesize, 1,
|
|
s->rects[0].w, transp_color))
|
|
y2--;
|
|
x1 = 0;
|
|
while (x1 < (s->rects[0].w - 1) && is_transp(s->rects[0].bitmap + x1, s->rects[0].linesize,
|
|
s->rects[0].h, transp_color))
|
|
x1++;
|
|
x2 = s->rects[0].w - 1;
|
|
while (x2 > 0 && is_transp(s->rects[0].bitmap + x2, s->rects[0].linesize, s->rects[0].h,
|
|
transp_color))
|
|
x2--;
|
|
w = x2 - x1 + 1;
|
|
h = y2 - y1 + 1;
|
|
bitmap = av_malloc(w * h);
|
|
if (!bitmap)
|
|
return 1;
|
|
for(y = 0; y < h; y++) {
|
|
memcpy(bitmap + w * y, s->rects[0].bitmap + x1 + (y1 + y) * s->rects[0].linesize, w);
|
|
}
|
|
av_freep(&s->rects[0].bitmap);
|
|
s->rects[0].bitmap = bitmap;
|
|
s->rects[0].linesize = w;
|
|
s->rects[0].w = w;
|
|
s->rects[0].h = h;
|
|
s->rects[0].x += x1;
|
|
s->rects[0].y += y1;
|
|
return 1;
|
|
}
|
|
|
|
static int dvdsub_close_decoder(AVCodecContext *avctx)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
#undef fprintf
|
|
static void ppm_save(const char *filename, uint8_t *bitmap, int w, int h,
|
|
uint32_t *rgba_palette)
|
|
{
|
|
int x, y, v;
|
|
FILE *f;
|
|
|
|
f = fopen(filename, "w");
|
|
if (!f) {
|
|
perror(filename);
|
|
exit(1);
|
|
}
|
|
fprintf(f, "P6\n"
|
|
"%d %d\n"
|
|
"%d\n",
|
|
w, h, 255);
|
|
for(y = 0; y < h; y++) {
|
|
for(x = 0; x < w; x++) {
|
|
v = rgba_palette[bitmap[y * w + x]];
|
|
putc((v >> 16) & 0xff, f);
|
|
putc((v >> 8) & 0xff, f);
|
|
putc((v >> 0) & 0xff, f);
|
|
}
|
|
}
|
|
fclose(f);
|
|
}
|
|
#endif
|
|
|
|
static int dvdsub_decode(AVCodecContext *avctx,
|
|
void *data, int *data_size,
|
|
uint8_t *buf, int buf_size)
|
|
{
|
|
AVSubtitle *sub = (void *)data;
|
|
|
|
if (decode_dvd_subtitles(sub, buf, buf_size) < 0) {
|
|
no_subtitle:
|
|
*data_size = 0;
|
|
|
|
return buf_size;
|
|
}
|
|
if (find_smallest_bouding_rectangle(sub) == 0)
|
|
goto no_subtitle;
|
|
|
|
#if defined(DEBUG)
|
|
av_log(NULL, AV_LOG_INFO, "start=%d ms end =%d ms\n",
|
|
sub->start_display_time,
|
|
sub->end_display_time);
|
|
ppm_save("/tmp/a.ppm", sub->rects[0].bitmap,
|
|
sub->rects[0].w, sub->rects[0].h, sub->rects[0].rgba_palette);
|
|
#endif
|
|
|
|
*data_size = 1;
|
|
return buf_size;
|
|
}
|
|
|
|
AVCodec dvdsub_decoder = {
|
|
"dvdsub",
|
|
CODEC_TYPE_SUBTITLE,
|
|
CODEC_ID_DVD_SUBTITLE,
|
|
sizeof(DVDSubContext),
|
|
dvdsub_init_decoder,
|
|
NULL,
|
|
dvdsub_close_decoder,
|
|
dvdsub_decode,
|
|
};
|
|
|
|
/* parser definition */
|
|
typedef struct DVDSubParseContext {
|
|
uint8_t *packet;
|
|
int packet_len;
|
|
int packet_index;
|
|
} DVDSubParseContext;
|
|
|
|
static int dvdsub_parse_init(AVCodecParserContext *s)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int dvdsub_parse(AVCodecParserContext *s,
|
|
AVCodecContext *avctx,
|
|
uint8_t **poutbuf, int *poutbuf_size,
|
|
const uint8_t *buf, int buf_size)
|
|
{
|
|
DVDSubParseContext *pc = s->priv_data;
|
|
|
|
if (pc->packet_index == 0) {
|
|
if (buf_size < 2)
|
|
return 0;
|
|
pc->packet_len = (buf[0] << 8) | buf[1];
|
|
av_freep(&pc->packet);
|
|
pc->packet = av_malloc(pc->packet_len);
|
|
}
|
|
if (pc->packet) {
|
|
if (pc->packet_index + buf_size <= pc->packet_len) {
|
|
memcpy(pc->packet + pc->packet_index, buf, buf_size);
|
|
pc->packet_index += buf_size;
|
|
if (pc->packet_index >= pc->packet_len) {
|
|
*poutbuf = pc->packet;
|
|
*poutbuf_size = pc->packet_len;
|
|
pc->packet_index = 0;
|
|
return buf_size;
|
|
}
|
|
} else {
|
|
/* erroneous size */
|
|
pc->packet_index = 0;
|
|
}
|
|
}
|
|
*poutbuf = NULL;
|
|
*poutbuf_size = 0;
|
|
return buf_size;
|
|
}
|
|
|
|
static void dvdsub_parse_close(AVCodecParserContext *s)
|
|
{
|
|
DVDSubParseContext *pc = s->priv_data;
|
|
av_freep(&pc->packet);
|
|
}
|
|
|
|
AVCodecParser dvdsub_parser = {
|
|
{ CODEC_ID_DVD_SUBTITLE },
|
|
sizeof(DVDSubParseContext),
|
|
dvdsub_parse_init,
|
|
dvdsub_parse,
|
|
dvdsub_parse_close,
|
|
};
|