0,0 → 1,219 |
/* |
* 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 |
|
/** |
* 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, const AVSubtitle *h) |
{ |
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 a 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", |
.long_name = NULL_IF_CONFIG_SMALL("DivX subtitles (XSUB)"), |
.type = AVMEDIA_TYPE_SUBTITLE, |
.id = AV_CODEC_ID_XSUB, |
.init = xsub_encoder_init, |
.encode_sub = xsub_encode, |
}; |