/libavcodec/dvbsub_parser.c
http://github.com/FFmpeg/FFmpeg · C · 188 lines · 131 code · 34 blank · 23 comment · 38 complexity · 960050003efbe6627dce7ebe64942926 MD5 · raw file
- /*
- * DVB subtitle parser for FFmpeg
- * Copyright (c) 2005 Ian Caulfield
- *
- * 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 <inttypes.h>
- #include <string.h>
- #include "libavutil/intreadwrite.h"
- #include "libavutil/mem.h"
- #include "avcodec.h"
- #include "internal.h"
- /* Parser (mostly) copied from dvdsub.c */
- #define PARSE_BUF_SIZE (65536)
- /* parser definition */
- typedef struct DVBSubParseContext {
- uint8_t *packet_buf;
- int packet_start;
- int packet_index;
- int in_packet;
- } DVBSubParseContext;
- static av_cold int dvbsub_parse_init(AVCodecParserContext *s)
- {
- DVBSubParseContext *pc = s->priv_data;
- pc->packet_buf = av_malloc(PARSE_BUF_SIZE);
- return 0;
- }
- static int dvbsub_parse(AVCodecParserContext *s,
- AVCodecContext *avctx,
- const uint8_t **poutbuf, int *poutbuf_size,
- const uint8_t *buf, int buf_size)
- {
- DVBSubParseContext *pc = s->priv_data;
- uint8_t *p, *p_end;
- int i, len, buf_pos = 0;
- int out_size = 0;
- ff_dlog(avctx, "DVB parse packet pts=%"PRIx64", lpts=%"PRIx64", cpts=%"PRIx64":\n",
- s->pts, s->last_pts, s->cur_frame_pts[s->cur_frame_start_index]);
- for (i=0; i < buf_size; i++)
- {
- ff_dlog(avctx, "%02x ", buf[i]);
- if (i % 16 == 15)
- ff_dlog(avctx, "\n");
- }
- if (i % 16 != 0)
- ff_dlog(avctx, "\n");
- *poutbuf = buf;
- *poutbuf_size = buf_size;
- s->fetch_timestamp = 1;
- if (s->last_pts != s->pts && s->pts != AV_NOPTS_VALUE) /* Start of a new packet */
- {
- if (pc->packet_index != pc->packet_start)
- {
- ff_dlog(avctx, "Discarding %d bytes\n",
- pc->packet_index - pc->packet_start);
- }
- pc->packet_start = 0;
- pc->packet_index = 0;
- if (buf_size < 2 || buf[0] != 0x20 || buf[1] != 0x00) {
- ff_dlog(avctx, "Bad packet header\n");
- return buf_size;
- }
- buf_pos = 2;
- pc->in_packet = 1;
- } else {
- if (pc->packet_start != 0)
- {
- if (pc->packet_index != pc->packet_start)
- {
- memmove(pc->packet_buf, pc->packet_buf + pc->packet_start,
- pc->packet_index - pc->packet_start);
- pc->packet_index -= pc->packet_start;
- pc->packet_start = 0;
- } else {
- pc->packet_start = 0;
- pc->packet_index = 0;
- }
- }
- }
- if (buf_size - buf_pos + pc->packet_index > PARSE_BUF_SIZE)
- return buf_size;
- /* if not currently in a packet, pass data */
- if (pc->in_packet == 0)
- return buf_size;
- memcpy(pc->packet_buf + pc->packet_index, buf + buf_pos, buf_size - buf_pos);
- pc->packet_index += buf_size - buf_pos;
- p = pc->packet_buf;
- p_end = pc->packet_buf + pc->packet_index;
- while (p < p_end)
- {
- if (*p == 0x0f)
- {
- if (6 <= p_end - p)
- {
- len = AV_RB16(p + 4);
- if (len + 6 <= p_end - p)
- {
- out_size += len + 6;
- p += len + 6;
- } else
- break;
- } else
- break;
- } else if (*p == 0xff) {
- if (1 < p_end - p)
- {
- ff_dlog(avctx, "Junk at end of packet\n");
- }
- pc->packet_index = p - pc->packet_buf;
- pc->in_packet = 0;
- break;
- } else {
- av_log(avctx, AV_LOG_ERROR, "Junk in packet\n");
- pc->packet_index = p - pc->packet_buf;
- pc->in_packet = 0;
- break;
- }
- }
- if (out_size > 0)
- {
- *poutbuf = pc->packet_buf;
- *poutbuf_size = out_size;
- pc->packet_start = *poutbuf_size;
- }
- if (s->pts == AV_NOPTS_VALUE)
- s->pts = s->last_pts;
- return buf_size;
- }
- static av_cold void dvbsub_parse_close(AVCodecParserContext *s)
- {
- DVBSubParseContext *pc = s->priv_data;
- av_freep(&pc->packet_buf);
- }
- AVCodecParser ff_dvbsub_parser = {
- .codec_ids = { AV_CODEC_ID_DVB_SUBTITLE },
- .priv_data_size = sizeof(DVBSubParseContext),
- .parser_init = dvbsub_parse_init,
- .parser_parse = dvbsub_parse,
- .parser_close = dvbsub_parse_close,
- };