LCOV - code coverage report
Current view: top level - libavcodec - xsubdec.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 0 91 0.0 %
Date: 2017-12-12 11:08:38 Functions: 0 3 0.0 %

          Line data    Source code
       1             : /*
       2             :  * XSUB subtitle decoder
       3             :  * Copyright (c) 2007 Reimar Döffinger
       4             :  *
       5             :  * This file is part of FFmpeg.
       6             :  *
       7             :  * FFmpeg is free software; you can redistribute it and/or
       8             :  * modify it under the terms of the GNU Lesser General Public
       9             :  * License as published by the Free Software Foundation; either
      10             :  * version 2.1 of the License, or (at your option) any later version.
      11             :  *
      12             :  * FFmpeg is distributed in the hope that it will be useful,
      13             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      14             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      15             :  * Lesser General Public License for more details.
      16             :  *
      17             :  * You should have received a copy of the GNU Lesser General Public
      18             :  * License along with FFmpeg; if not, write to the Free Software
      19             :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
      20             :  */
      21             : 
      22             : #include "libavutil/mathematics.h"
      23             : #include "libavutil/imgutils.h"
      24             : #include "avcodec.h"
      25             : #include "get_bits.h"
      26             : #include "bytestream.h"
      27             : 
      28           0 : static av_cold int decode_init(AVCodecContext *avctx) {
      29           0 :     avctx->pix_fmt = AV_PIX_FMT_PAL8;
      30           0 :     return 0;
      31             : }
      32             : 
      33             : static const uint8_t tc_offsets[9] = { 0, 1, 3, 4, 6, 7, 9, 10, 11 };
      34             : static const uint8_t tc_muls[9] = { 10, 6, 10, 6, 10, 10, 10, 10, 1 };
      35             : 
      36           0 : static int64_t parse_timecode(const uint8_t *buf, int64_t packet_time) {
      37             :     int i;
      38           0 :     int64_t ms = 0;
      39           0 :     if (buf[2] != ':' || buf[5] != ':' || buf[8] != '.')
      40           0 :         return AV_NOPTS_VALUE;
      41           0 :     for (i = 0; i < sizeof(tc_offsets); i++) {
      42           0 :         uint8_t c = buf[tc_offsets[i]] - '0';
      43           0 :         if (c > 9) return AV_NOPTS_VALUE;
      44           0 :         ms = (ms + c) * tc_muls[i];
      45             :     }
      46           0 :     return ms - packet_time;
      47             : }
      48             : 
      49           0 : static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
      50             :                         AVPacket *avpkt) {
      51           0 :     const uint8_t *buf = avpkt->data;
      52           0 :     int buf_size = avpkt->size;
      53           0 :     AVSubtitle *sub = data;
      54           0 :     const uint8_t *buf_end = buf + buf_size;
      55             :     uint8_t *bitmap;
      56             :     int w, h, x, y, i, ret;
      57           0 :     int64_t packet_time = 0;
      58             :     GetBitContext gb;
      59           0 :     int has_alpha = avctx->codec_tag == MKTAG('D','X','S','A');
      60             : 
      61             :     // check that at least header fits
      62           0 :     if (buf_size < 27 + 7 * 2 + 4 * (3 + has_alpha)) {
      63           0 :         av_log(avctx, AV_LOG_ERROR, "coded frame size %d too small\n", buf_size);
      64           0 :         return -1;
      65             :     }
      66             : 
      67             :     // read start and end time
      68           0 :     if (buf[0] != '[' || buf[13] != '-' || buf[26] != ']') {
      69           0 :         av_log(avctx, AV_LOG_ERROR, "invalid time code\n");
      70           0 :         return -1;
      71             :     }
      72           0 :     if (avpkt->pts != AV_NOPTS_VALUE)
      73           0 :         packet_time = av_rescale_q(avpkt->pts, AV_TIME_BASE_Q, (AVRational){1, 1000});
      74           0 :     sub->start_display_time = parse_timecode(buf +  1, packet_time);
      75           0 :     sub->end_display_time   = parse_timecode(buf + 14, packet_time);
      76           0 :     buf += 27;
      77             : 
      78             :     // read header
      79           0 :     w = bytestream_get_le16(&buf);
      80           0 :     h = bytestream_get_le16(&buf);
      81           0 :     if (av_image_check_size(w, h, 0, avctx) < 0)
      82           0 :         return -1;
      83           0 :     x = bytestream_get_le16(&buf);
      84           0 :     y = bytestream_get_le16(&buf);
      85             :     // skip bottom right position, it gives no new information
      86           0 :     bytestream_get_le16(&buf);
      87           0 :     bytestream_get_le16(&buf);
      88             :     // The following value is supposed to indicate the start offset
      89             :     // (relative to the palette) of the data for the second field,
      90             :     // however there are files in which it has a bogus value and thus
      91             :     // we just ignore it
      92           0 :     bytestream_get_le16(&buf);
      93             : 
      94           0 :     if (buf_end - buf < h + 3*4)
      95           0 :         return AVERROR_INVALIDDATA;
      96             : 
      97             :     // allocate sub and set values
      98           0 :     sub->rects =  av_mallocz(sizeof(*sub->rects));
      99           0 :     if (!sub->rects)
     100           0 :         return AVERROR(ENOMEM);
     101             : 
     102           0 :     sub->rects[0] = av_mallocz(sizeof(*sub->rects[0]));
     103           0 :     if (!sub->rects[0]) {
     104           0 :         av_freep(&sub->rects);
     105           0 :         return AVERROR(ENOMEM);
     106             :     }
     107           0 :     sub->rects[0]->x = x; sub->rects[0]->y = y;
     108           0 :     sub->rects[0]->w = w; sub->rects[0]->h = h;
     109           0 :     sub->rects[0]->type = SUBTITLE_BITMAP;
     110           0 :     sub->rects[0]->linesize[0] = w;
     111           0 :     sub->rects[0]->data[0] = av_malloc(w * h);
     112           0 :     sub->rects[0]->nb_colors = 4;
     113           0 :     sub->rects[0]->data[1] = av_mallocz(AVPALETTE_SIZE);
     114           0 :     if (!sub->rects[0]->data[0] || !sub->rects[0]->data[1]) {
     115           0 :         av_freep(&sub->rects[0]->data[1]);
     116           0 :         av_freep(&sub->rects[0]->data[0]);
     117           0 :         av_freep(&sub->rects[0]);
     118           0 :         av_freep(&sub->rects);
     119           0 :         return AVERROR(ENOMEM);
     120             :     }
     121           0 :     sub->num_rects = 1;
     122             : 
     123             :     // read palette
     124           0 :     for (i = 0; i < sub->rects[0]->nb_colors; i++)
     125           0 :         ((uint32_t*)sub->rects[0]->data[1])[i] = bytestream_get_be24(&buf);
     126             : 
     127           0 :     if (!has_alpha) {
     128             :         // make all except background (first entry) non-transparent
     129           0 :         for (i = 1; i < sub->rects[0]->nb_colors; i++)
     130           0 :             ((uint32_t *)sub->rects[0]->data[1])[i] |= 0xff000000;
     131             :     } else {
     132           0 :         for (i = 0; i < sub->rects[0]->nb_colors; i++)
     133           0 :             ((uint32_t *)sub->rects[0]->data[1])[i] |= *buf++ << 24;
     134             :     }
     135             : 
     136             : #if FF_API_AVPICTURE
     137             : FF_DISABLE_DEPRECATION_WARNINGS
     138             : {
     139             :     AVSubtitleRect *rect;
     140             :     int j;
     141           0 :     rect = sub->rects[0];
     142           0 :     for (j = 0; j < 4; j++) {
     143           0 :         rect->pict.data[j] = rect->data[j];
     144           0 :         rect->pict.linesize[j] = rect->linesize[j];
     145             :     }
     146             : }
     147             : FF_ENABLE_DEPRECATION_WARNINGS
     148             : #endif
     149             : 
     150             :     // process RLE-compressed data
     151           0 :     if ((ret = init_get_bits8(&gb, buf, buf_end - buf)) < 0)
     152           0 :         return ret;
     153           0 :     bitmap = sub->rects[0]->data[0];
     154           0 :     for (y = 0; y < h; y++) {
     155             :         // interlaced: do odd lines
     156           0 :         if (y == (h + 1) / 2) bitmap = sub->rects[0]->data[0] + w;
     157           0 :         for (x = 0; x < w; ) {
     158           0 :             int log2 = ff_log2_tab[show_bits(&gb, 8)];
     159           0 :             int run = get_bits(&gb, 14 - 4 * (log2 >> 1));
     160           0 :             int color = get_bits(&gb, 2);
     161           0 :             run = FFMIN(run, w - x);
     162             :             // run length 0 means till end of row
     163           0 :             if (!run) run = w - x;
     164           0 :             memset(bitmap, color, run);
     165           0 :             bitmap += run;
     166           0 :             x += run;
     167             :         }
     168             :         // interlaced, skip every second line
     169           0 :         bitmap += w;
     170           0 :         align_get_bits(&gb);
     171             :     }
     172           0 :     *data_size = 1;
     173           0 :     return buf_size;
     174             : }
     175             : 
     176             : AVCodec ff_xsub_decoder = {
     177             :     .name      = "xsub",
     178             :     .long_name = NULL_IF_CONFIG_SMALL("XSUB"),
     179             :     .type      = AVMEDIA_TYPE_SUBTITLE,
     180             :     .id        = AV_CODEC_ID_XSUB,
     181             :     .init      = decode_init,
     182             :     .decode    = decode_frame,
     183             : };

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