mirror of https://git.ffmpeg.org/ffmpeg.git
221 lines
7.1 KiB
C
221 lines
7.1 KiB
C
/*
|
|
* DivX (XSUB) subtitle encoder
|
|
* Copyright (c) 2005 DivX, Inc.
|
|
* Copyright (c) 2009 Bjorn Axelsson
|
|
*
|
|
* This file is part of Libav.
|
|
*
|
|
* Libav 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.
|
|
*
|
|
* Libav 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 Libav; 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"
|
|
#include "put_bits.h"
|
|
|
|
/**
|
|
* Number of pixels to pad left and right.
|
|
*
|
|
* The official encoder pads the subtitles with two pixels on either side,
|
|
* but until we find out why, we won't do it (we will pad to have width
|
|
* divisible by 2 though).
|
|
*/
|
|
#define PADDING 0
|
|
#define PADDING_COLOR 0
|
|
|
|
/**
|
|
* Encode a single color run. At most 16 bits will be used.
|
|
* @param len length of the run, values > 255 mean "until end of line", may not be < 0.
|
|
* @param color color to encode, only the lowest two bits are used and all others must be 0.
|
|
*/
|
|
static void put_xsub_rle(PutBitContext *pb, int len, int color)
|
|
{
|
|
if (len <= 255)
|
|
put_bits(pb, 2 + ((ff_log2_tab[len] >> 1) << 2), len);
|
|
else
|
|
put_bits(pb, 14, 0);
|
|
put_bits(pb, 2, color);
|
|
}
|
|
|
|
/**
|
|
* Encode a 4-color bitmap with XSUB rle.
|
|
*
|
|
* The encoded bitmap may be wider than the source bitmap due to padding.
|
|
*/
|
|
static int xsub_encode_rle(PutBitContext *pb, const uint8_t *bitmap,
|
|
int linesize, int w, int h)
|
|
{
|
|
int x0, x1, y, len, color = PADDING_COLOR;
|
|
|
|
for (y = 0; y < h; y++) {
|
|
x0 = 0;
|
|
while (x0 < w) {
|
|
// Make sure we have enough room for at least one run and padding
|
|
if (pb->size_in_bits - put_bits_count(pb) < 7*8)
|
|
return -1;
|
|
|
|
x1 = x0;
|
|
color = bitmap[x1++] & 3;
|
|
while (x1 < w && (bitmap[x1] & 3) == color)
|
|
x1++;
|
|
len = x1 - x0;
|
|
if (PADDING && x0 == 0) {
|
|
if (color == PADDING_COLOR) {
|
|
len += PADDING;
|
|
x0 -= PADDING;
|
|
} else
|
|
put_xsub_rle(pb, PADDING, PADDING_COLOR);
|
|
}
|
|
|
|
// Run can't be longer than 255, unless it is the rest of a row
|
|
if (x1 == w && color == PADDING_COLOR) {
|
|
len += PADDING + (w&1);
|
|
} else
|
|
len = FFMIN(len, 255);
|
|
put_xsub_rle(pb, len, color);
|
|
|
|
x0 += len;
|
|
}
|
|
if (color != PADDING_COLOR && (PADDING + (w&1)))
|
|
put_xsub_rle(pb, PADDING + (w&1), PADDING_COLOR);
|
|
|
|
avpriv_align_put_bits(pb);
|
|
|
|
bitmap += linesize;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int make_tc(uint64_t ms, int *tc)
|
|
{
|
|
static const int tc_divs[3] = { 1000, 60, 60 };
|
|
int i;
|
|
for (i=0; i<3; i++) {
|
|
tc[i] = ms % tc_divs[i];
|
|
ms /= tc_divs[i];
|
|
}
|
|
tc[3] = ms;
|
|
return ms > 99;
|
|
}
|
|
|
|
static int xsub_encode(AVCodecContext *avctx, unsigned char *buf,
|
|
int bufsize, void *data)
|
|
{
|
|
AVSubtitle *h = data;
|
|
uint64_t startTime = h->pts / 1000; // FIXME: need better solution...
|
|
uint64_t endTime = startTime + h->end_display_time - h->start_display_time;
|
|
int start_tc[4], end_tc[4];
|
|
uint8_t *hdr = buf + 27; // Point behind the timestamp
|
|
uint8_t *rlelenptr;
|
|
uint16_t width, height;
|
|
int i;
|
|
PutBitContext pb;
|
|
|
|
if (bufsize < 27 + 7*2 + 4*3) {
|
|
av_log(avctx, AV_LOG_ERROR, "Buffer too small for XSUB header.\n");
|
|
return -1;
|
|
}
|
|
|
|
// TODO: support multiple rects
|
|
if (h->num_rects > 1)
|
|
av_log(avctx, AV_LOG_WARNING, "Only single rects supported (%d in subtitle.)\n", h->num_rects);
|
|
|
|
// TODO: render text-based subtitles into bitmaps
|
|
if (!h->rects[0]->pict.data[0] || !h->rects[0]->pict.data[1]) {
|
|
av_log(avctx, AV_LOG_WARNING, "No subtitle bitmap available.\n");
|
|
return -1;
|
|
}
|
|
|
|
// TODO: color reduction, similar to dvdsub encoder
|
|
if (h->rects[0]->nb_colors > 4)
|
|
av_log(avctx, AV_LOG_WARNING, "No more than 4 subtitle colors supported (%d found.)\n", h->rects[0]->nb_colors);
|
|
|
|
// TODO: Palette swapping if color zero is not transparent
|
|
if (((uint32_t *)h->rects[0]->pict.data[1])[0] & 0xff)
|
|
av_log(avctx, AV_LOG_WARNING, "Color index 0 is not transparent. Transparency will be messed up.\n");
|
|
|
|
if (make_tc(startTime, start_tc) || make_tc(endTime, end_tc)) {
|
|
av_log(avctx, AV_LOG_WARNING, "Time code >= 100 hours.\n");
|
|
return -1;
|
|
}
|
|
|
|
snprintf(buf, 28,
|
|
"[%02d:%02d:%02d.%03d-%02d:%02d:%02d.%03d]",
|
|
start_tc[3], start_tc[2], start_tc[1], start_tc[0],
|
|
end_tc[3], end_tc[2], end_tc[1], end_tc[0]);
|
|
|
|
// Width and height must probably be multiples of 2.
|
|
// 2 pixels required on either side of subtitle.
|
|
// Possibly due to limitations of hardware renderers.
|
|
// TODO: check if the bitmap is already padded
|
|
width = FFALIGN(h->rects[0]->w, 2) + PADDING * 2;
|
|
height = FFALIGN(h->rects[0]->h, 2);
|
|
|
|
bytestream_put_le16(&hdr, width);
|
|
bytestream_put_le16(&hdr, height);
|
|
bytestream_put_le16(&hdr, h->rects[0]->x);
|
|
bytestream_put_le16(&hdr, h->rects[0]->y);
|
|
bytestream_put_le16(&hdr, h->rects[0]->x + width);
|
|
bytestream_put_le16(&hdr, h->rects[0]->y + height);
|
|
|
|
rlelenptr = hdr; // Will store length of first field here later.
|
|
hdr+=2;
|
|
|
|
// Palette
|
|
for (i=0; i<4; i++)
|
|
bytestream_put_be24(&hdr, ((uint32_t *)h->rects[0]->pict.data[1])[i]);
|
|
|
|
// Bitmap
|
|
// RLE buffer. Reserve 2 bytes for possible padding after the last row.
|
|
init_put_bits(&pb, hdr, bufsize - (hdr - buf) - 2);
|
|
if (xsub_encode_rle(&pb, h->rects[0]->pict.data[0],
|
|
h->rects[0]->pict.linesize[0]*2,
|
|
h->rects[0]->w, (h->rects[0]->h + 1) >> 1))
|
|
return -1;
|
|
bytestream_put_le16(&rlelenptr, put_bits_count(&pb) >> 3); // Length of first field
|
|
|
|
if (xsub_encode_rle(&pb, h->rects[0]->pict.data[0] + h->rects[0]->pict.linesize[0],
|
|
h->rects[0]->pict.linesize[0]*2,
|
|
h->rects[0]->w, h->rects[0]->h >> 1))
|
|
return -1;
|
|
|
|
// Enforce total height to be be multiple of 2
|
|
if (h->rects[0]->h & 1) {
|
|
put_xsub_rle(&pb, h->rects[0]->w, PADDING_COLOR);
|
|
avpriv_align_put_bits(&pb);
|
|
}
|
|
|
|
flush_put_bits(&pb);
|
|
|
|
return hdr - buf + put_bits_count(&pb)/8;
|
|
}
|
|
|
|
static av_cold int xsub_encoder_init(AVCodecContext *avctx)
|
|
{
|
|
if (!avctx->codec_tag)
|
|
avctx->codec_tag = MKTAG('D','X','S','B');
|
|
|
|
return 0;
|
|
}
|
|
|
|
AVCodec ff_xsub_encoder = {
|
|
.name = "xsub",
|
|
.type = AVMEDIA_TYPE_SUBTITLE,
|
|
.id = CODEC_ID_XSUB,
|
|
.init = xsub_encoder_init,
|
|
.encode = xsub_encode,
|
|
.long_name = NULL_IF_CONFIG_SMALL("DivX subtitles (XSUB)"),
|
|
};
|