FFmpeg/libavcodec/dvdsubenc.c
Stefano Sabatini 72415b2adb Define AVMediaType enum, and use it instead of enum CodecType, which
is deprecated and will be dropped at the next major bump.

Originally committed as revision 22735 to svn://svn.ffmpeg.org/ffmpeg/trunk
2010-03-30 23:30:55 +00:00

227 lines
6.9 KiB
C

/*
* DVD subtitle encoding for ffmpeg
* Copyright (c) 2005 Wolfram Gloger
*
* This file is part of FFmpeg.
*
* FFmpeg 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 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avcodec.h"
#include "bytestream.h"
#undef NDEBUG
#include <assert.h>
// ncnt is the nibble counter
#define PUTNIBBLE(val)\
do {\
if (ncnt++ & 1)\
*q++ = bitbuf | ((val) & 0x0f);\
else\
bitbuf = (val) << 4;\
} while(0)
static void dvd_encode_rle(uint8_t **pq,
const uint8_t *bitmap, int linesize,
int w, int h,
const int cmap[256])
{
uint8_t *q;
unsigned int bitbuf = 0;
int ncnt;
int x, y, len, color;
q = *pq;
for (y = 0; y < h; ++y) {
ncnt = 0;
for(x = 0; x < w; x += len) {
color = bitmap[x];
for (len=1; x+len < w; ++len)
if (bitmap[x+len] != color)
break;
color = cmap[color];
assert(color < 4);
if (len < 0x04) {
PUTNIBBLE((len << 2)|color);
} else if (len < 0x10) {
PUTNIBBLE(len >> 2);
PUTNIBBLE((len << 2)|color);
} else if (len < 0x40) {
PUTNIBBLE(0);
PUTNIBBLE(len >> 2);
PUTNIBBLE((len << 2)|color);
} else if (x+len == w) {
PUTNIBBLE(0);
PUTNIBBLE(0);
PUTNIBBLE(0);
PUTNIBBLE(color);
} else {
if (len > 0xff)
len = 0xff;
PUTNIBBLE(0);
PUTNIBBLE(len >> 6);
PUTNIBBLE(len >> 2);
PUTNIBBLE((len << 2)|color);
}
}
/* end of line */
if (ncnt & 1)
PUTNIBBLE(0);
bitmap += linesize;
}
*pq = q;
}
static int encode_dvd_subtitles(uint8_t *outbuf, int outbuf_size,
const AVSubtitle *h)
{
uint8_t *q, *qq;
int object_id;
int offset1[20], offset2[20];
int i, imax, color, alpha, rects = h->num_rects;
unsigned long hmax;
unsigned long hist[256];
int cmap[256];
if (rects == 0 || h->rects == NULL)
return -1;
if (rects > 20)
rects = 20;
// analyze bitmaps, compress to 4 colors
for (i=0; i<256; ++i) {
hist[i] = 0;
cmap[i] = 0;
}
for (object_id = 0; object_id < rects; object_id++)
for (i=0; i<h->rects[object_id]->w*h->rects[object_id]->h; ++i) {
color = h->rects[object_id]->pict.data[0][i];
// only count non-transparent pixels
alpha = ((uint32_t*)h->rects[object_id]->pict.data[1])[color] >> 24;
hist[color] += alpha;
}
for (color=3;; --color) {
hmax = 0;
imax = 0;
for (i=0; i<256; ++i)
if (hist[i] > hmax) {
imax = i;
hmax = hist[i];
}
if (hmax == 0)
break;
if (color == 0)
color = 3;
av_log(NULL, AV_LOG_DEBUG, "dvd_subtitle hist[%d]=%ld -> col %d\n",
imax, hist[imax], color);
cmap[imax] = color;
hist[imax] = 0;
}
// encode data block
q = outbuf + 4;
for (object_id = 0; object_id < rects; object_id++) {
offset1[object_id] = q - outbuf;
// worst case memory requirement: 1 nibble per pixel..
if ((q - outbuf) + h->rects[object_id]->w*h->rects[object_id]->h/2
+ 17*rects + 21 > outbuf_size) {
av_log(NULL, AV_LOG_ERROR, "dvd_subtitle too big\n");
return -1;
}
dvd_encode_rle(&q, h->rects[object_id]->pict.data[0],
h->rects[object_id]->w*2,
h->rects[object_id]->w, h->rects[object_id]->h >> 1,
cmap);
offset2[object_id] = q - outbuf;
dvd_encode_rle(&q, h->rects[object_id]->pict.data[0] + h->rects[object_id]->w,
h->rects[object_id]->w*2,
h->rects[object_id]->w, h->rects[object_id]->h >> 1,
cmap);
}
// set data packet size
qq = outbuf + 2;
bytestream_put_be16(&qq, q - outbuf);
// send start display command
bytestream_put_be16(&q, (h->start_display_time*90) >> 10);
bytestream_put_be16(&q, (q - outbuf) /*- 2 */ + 8 + 12*rects + 2);
*q++ = 0x03; // palette - 4 nibbles
*q++ = 0x03; *q++ = 0x7f;
*q++ = 0x04; // alpha - 4 nibbles
*q++ = 0xf0; *q++ = 0x00;
//*q++ = 0x0f; *q++ = 0xff;
// XXX not sure if more than one rect can really be encoded..
// 12 bytes per rect
for (object_id = 0; object_id < rects; object_id++) {
int x2 = h->rects[object_id]->x + h->rects[object_id]->w - 1;
int y2 = h->rects[object_id]->y + h->rects[object_id]->h - 1;
*q++ = 0x05;
// x1 x2 -> 6 nibbles
*q++ = h->rects[object_id]->x >> 4;
*q++ = (h->rects[object_id]->x << 4) | ((x2 >> 8) & 0xf);
*q++ = x2;
// y1 y2 -> 6 nibbles
*q++ = h->rects[object_id]->y >> 4;
*q++ = (h->rects[object_id]->y << 4) | ((y2 >> 8) & 0xf);
*q++ = y2;
*q++ = 0x06;
// offset1, offset2
bytestream_put_be16(&q, offset1[object_id]);
bytestream_put_be16(&q, offset2[object_id]);
}
*q++ = 0x01; // start command
*q++ = 0xff; // terminating command
// send stop display command last
bytestream_put_be16(&q, (h->end_display_time*90) >> 10);
bytestream_put_be16(&q, (q - outbuf) - 2 /*+ 4*/);
*q++ = 0x02; // set end
*q++ = 0xff; // terminating command
qq = outbuf;
bytestream_put_be16(&qq, q - outbuf);
av_log(NULL, AV_LOG_DEBUG, "subtitle_packet size=%td\n", q - outbuf);
return q - outbuf;
}
static int dvdsub_encode(AVCodecContext *avctx,
unsigned char *buf, int buf_size, void *data)
{
//DVDSubtitleContext *s = avctx->priv_data;
AVSubtitle *sub = data;
int ret;
ret = encode_dvd_subtitles(buf, buf_size, sub);
return ret;
}
AVCodec dvdsub_encoder = {
"dvdsub",
AVMEDIA_TYPE_SUBTITLE,
CODEC_ID_DVD_SUBTITLE,
0,
NULL,
dvdsub_encode,
.long_name = NULL_IF_CONFIG_SMALL("DVD subtitles"),
};