Commit a4276ba2 authored by Reimar Döffinger's avatar Reimar Döffinger
Browse files

Add support for encoding XSUB subtitles. Muxing support is still missing.

Based on code by DivX, Inc., heavily changed by Björn Axelsson [gecko acc.umu.se] and me.

Originally committed as revision 19222 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent 4bbe788a
......@@ -25,6 +25,7 @@ version <next>:
- AMR-NB decoding/encoding, AMR-WB decoding via OpenCORE libraries
- DPX image decoder
- Electronic Arts Madcow decoder
- DivX (XSUB) subtitle encoder
......
......@@ -648,7 +648,7 @@ performance on systems without hardware floating point support).
@item SSA/ASS @tab X @tab X
@item DVB @tab X @tab X @tab X @tab X
@item DVD @tab X @tab X @tab X @tab X
@item XSUB @tab @tab @tab @tab X
@item XSUB @tab @tab @tab X @tab X
@end multitable
@code{X} means that the feature is supported.
......
......@@ -273,6 +273,7 @@ OBJS-$(CONFIG_XAN_WC3_DECODER) += xan.o
OBJS-$(CONFIG_XAN_WC4_DECODER) += xan.o
OBJS-$(CONFIG_XL_DECODER) += xl.o
OBJS-$(CONFIG_XSUB_DECODER) += xsubdec.o
OBJS-$(CONFIG_XSUB_ENCODER) += xsubenc.o
OBJS-$(CONFIG_ZLIB_DECODER) += lcldec.o
OBJS-$(CONFIG_ZLIB_ENCODER) += lclenc.o
OBJS-$(CONFIG_ZMBV_DECODER) += zmbv.o
......
......@@ -301,7 +301,7 @@ void avcodec_register_all(void)
/* subtitles */
REGISTER_ENCDEC (DVBSUB, dvbsub);
REGISTER_ENCDEC (DVDSUB, dvdsub);
REGISTER_DECODER (XSUB, xsub);
REGISTER_ENCDEC (XSUB, xsub);
/* external libraries */
REGISTER_ENCDEC (LIBAMR_NB, libamr_nb);
......
/*
* DivX (XSUB) subtitle encoder
* Copyright (c) 2005 DivX, Inc.
* Copyright (c) 2009 Bjorn Axelsson
*
* 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"
#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
/**
* Encodes 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);
}
/**
* Encodes 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);
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[3], 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);
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 xsub_encoder = {
"xsub",
CODEC_TYPE_SUBTITLE,
CODEC_ID_XSUB,
0,
xsub_encoder_init,
xsub_encode,
NULL,
.long_name = NULL_IF_CONFIG_SMALL("DivX subtitles (XSUB)"),
};
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