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-rw-r--r--Changelog1
-rw-r--r--doc/general.texi2
-rw-r--r--libavcodec/Makefile1
-rw-r--r--libavcodec/allcodecs.c2
-rw-r--r--libavcodec/xsubenc.c222
5 files changed, 226 insertions, 2 deletions
diff --git a/Changelog b/Changelog
index 5e5fcbe262..80f500a897 100644
--- a/Changelog
+++ b/Changelog
@@ -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
diff --git a/doc/general.texi b/doc/general.texi
index 0139b5fc33..2f155479cc 100644
--- a/doc/general.texi
+++ b/doc/general.texi
@@ -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.
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index da030fc889..503c5d4a3c 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -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
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index cd99e30ce4..4605859706 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -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);
diff --git a/libavcodec/xsubenc.c b/libavcodec/xsubenc.c
new file mode 100644
index 0000000000..55fcb627f5
--- /dev/null
+++ b/libavcodec/xsubenc.c
@@ -0,0 +1,222 @@
+/*
+ * 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)"),
+};
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-08 14:42:56 +0000