diff options
Diffstat (limited to 'contrib/ffmpeg/libavcodec/xsubdec.c')
| -rw-r--r-- | contrib/ffmpeg/libavcodec/xsubdec.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/contrib/ffmpeg/libavcodec/xsubdec.c b/contrib/ffmpeg/libavcodec/xsubdec.c new file mode 100644 index 000000000..391a003ac --- /dev/null +++ b/contrib/ffmpeg/libavcodec/xsubdec.c @@ -0,0 +1,136 @@ +/* + * XSUB subtitle decoder + * Copyright (c) 2007 Reimar Döffinger + * + * 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 "bitstream.h" +#include "bytestream.h" + +static int decode_init(AVCodecContext *avctx) { + avctx->pix_fmt = PIX_FMT_PAL8; + return 0; +} + +static const uint8_t tc_offsets[9] = { 0, 1, 3, 4, 6, 7, 9, 10, 11 }; +static const uint8_t tc_muls[9] = { 10, 6, 10, 6, 10, 6, 10, 10, 1 }; + +static uint64_t parse_timecode(const uint8_t *buf) { + int i; + int64_t ms = 0; + if (buf[2] != ':' || buf[5] != ':' || buf[8] != '.') + return AV_NOPTS_VALUE; + for (i = 0; i < sizeof(tc_offsets); i++) { + uint8_t c = buf[tc_offsets[i]] - '0'; + if (c > 9) return AV_NOPTS_VALUE; + ms = (ms + c) * tc_muls[i]; + } + return ms; +} + +static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, + const uint8_t *buf, int buf_size) { + AVSubtitle *sub = data; + const uint8_t *buf_end = buf + buf_size; + uint8_t *bitmap; + int w, h, x, y, rlelen, i; + GetBitContext gb; + + // check that at least header fits + if (buf_size < 27 + 7 * 2 + 4 * 3) { + av_log(avctx, AV_LOG_ERROR, "coded frame too small\n"); + return -1; + } + + // read start and end time + if (buf[0] != '[' || buf[13] != '-' || buf[26] != ']') { + av_log(avctx, AV_LOG_ERROR, "invalid time code\n"); + return -1; + } + sub->start_display_time = parse_timecode(buf + 1); + sub->end_display_time = parse_timecode(buf + 14); + buf += 27; + + // read header + w = bytestream_get_le16(&buf); + h = bytestream_get_le16(&buf); + if (avcodec_check_dimensions(avctx, w, h) < 0) + return -1; + x = bytestream_get_le16(&buf); + y = bytestream_get_le16(&buf); + // skip bottom right position, it gives no new information + bytestream_get_le16(&buf); + bytestream_get_le16(&buf); + rlelen = bytestream_get_le16(&buf); + + // allocate sub and set values + if (!sub->rects) { + sub->rects = av_mallocz(sizeof(AVSubtitleRect)); + sub->num_rects = 1; + } + av_freep(&sub->rects[0].bitmap); + sub->rects[0].x = x; sub->rects[0].y = y; + sub->rects[0].w = w; sub->rects[0].h = h; + sub->rects[0].linesize = w; + sub->rects[0].bitmap = av_malloc(w * h); + sub->rects[0].nb_colors = 4; + sub->rects[0].rgba_palette = av_malloc(sub->rects[0].nb_colors * 4); + + // read palette + for (i = 0; i < sub->rects[0].nb_colors; i++) + sub->rects[0].rgba_palette[i] = bytestream_get_be24(&buf); + // make all except background (first entry) non-transparent + for (i = 1; i < sub->rects[0].nb_colors; i++) + sub->rects[0].rgba_palette[i] |= 0xff000000; + + // process RLE-compressed data + rlelen = FFMIN(rlelen, buf_end - buf); + init_get_bits(&gb, buf, rlelen * 8); + bitmap = sub->rects[0].bitmap; + for (y = 0; y < h; y++) { + // interlaced: do odd lines + if (y == (h + 1) / 2) bitmap = sub->rects[0].bitmap + w; + for (x = 0; x < w; ) { + int log2 = ff_log2_tab[show_bits(&gb, 8)]; + int run = get_bits(&gb, 14 - 4 * (log2 >> 1)); + int color = get_bits(&gb, 2); + run = FFMIN(run, w - x); + // run length 0 means till end of row + if (!run) run = w - x; + memset(bitmap, color, run); + bitmap += run; + x += run; + } + // interlaced, skip every second line + bitmap += w; + align_get_bits(&gb); + } + *data_size = 1; + return buf_size; +} + +AVCodec xsub_decoder = { + "xsub", + CODEC_TYPE_SUBTITLE, + CODEC_ID_XSUB, + 0, + decode_init, + NULL, + NULL, + decode_frame, +}; |