From 98c98e04ccae75ccaf0f3ebf18588bc0090dff8b Mon Sep 17 00:00:00 2001 From: Diego Biurrun Date: Thu, 3 May 2007 23:50:24 +0000 Subject: Move dca parser to its own file. Originally committed as revision 8881 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/dca_parser.c | 127 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) create mode 100644 libavcodec/dca_parser.c (limited to 'libavcodec/dca_parser.c') diff --git a/libavcodec/dca_parser.c b/libavcodec/dca_parser.c new file mode 100644 index 0000000000..db66b474f3 --- /dev/null +++ b/libavcodec/dca_parser.c @@ -0,0 +1,127 @@ +/* + * DCA parser + * Copyright (C) 2004 Gildas Bazin + * Copyright (C) 2004 Benjamin Zores + * Copyright (C) 2006 Benjamin Larsson + * Copyright (C) 2007 Konstantin Shishkov + * + * 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 + */ + +/** + * @file dca_parser.c + */ + +#include "avcodec.h" +#include "parser.h" +#include "dca.h" + +typedef struct DCAParseContext { + ParseContext pc; + uint32_t lastmarker; +} DCAParseContext; + +#define IS_MARKER(state, i, buf, buf_size) \ + ((state == DCA_MARKER_14B_LE && (i < buf_size-2) && (buf[i+1] & 0xF0) == 0xF0 && buf[i+2] == 0x07) \ + || (state == DCA_MARKER_14B_BE && (i < buf_size-2) && buf[i+1] == 0x07 && (buf[i+2] & 0xF0) == 0xF0) \ + || state == DCA_MARKER_RAW_LE || state == DCA_MARKER_RAW_BE) + +/** + * finds the end of the current frame in the bitstream. + * @return the position of the first byte of the next frame, or -1 + */ +static int dca_find_frame_end(DCAParseContext * pc1, const uint8_t * buf, + int buf_size) +{ + int start_found, i; + uint32_t state; + ParseContext *pc = &pc1->pc; + + start_found = pc->frame_start_found; + state = pc->state; + + i = 0; + if (!start_found) { + for (i = 0; i < buf_size; i++) { + state = (state << 8) | buf[i]; + if (IS_MARKER(state, i, buf, buf_size)) { + if (pc1->lastmarker && state == pc1->lastmarker) { + start_found = 1; + break; + } else if (!pc1->lastmarker) { + start_found = 1; + pc1->lastmarker = state; + break; + } + } + } + } + if (start_found) { + for (; i < buf_size; i++) { + state = (state << 8) | buf[i]; + if (state == pc1->lastmarker && IS_MARKER(state, i, buf, buf_size)) { + pc->frame_start_found = 0; + pc->state = -1; + return i - 3; + } + } + } + pc->frame_start_found = start_found; + pc->state = state; + return END_NOT_FOUND; +} + +static int dca_parse_init(AVCodecParserContext * s) +{ + DCAParseContext *pc1 = s->priv_data; + + pc1->lastmarker = 0; + return 0; +} + +static int dca_parse(AVCodecParserContext * s, + AVCodecContext * avctx, + uint8_t ** poutbuf, int *poutbuf_size, + const uint8_t * buf, int buf_size) +{ + DCAParseContext *pc1 = s->priv_data; + ParseContext *pc = &pc1->pc; + int next; + + if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { + next = buf_size; + } else { + next = dca_find_frame_end(pc1, buf, buf_size); + + if (ff_combine_frame(pc, next, (uint8_t **) & buf, &buf_size) < 0) { + *poutbuf = NULL; + *poutbuf_size = 0; + return buf_size; + } + } + *poutbuf = (uint8_t *) buf; + *poutbuf_size = buf_size; + return next; +} + +AVCodecParser dca_parser = { + {CODEC_ID_DTS}, + sizeof(DCAParseContext), + dca_parse_init, + dca_parse, + ff_parse_close, +}; -- cgit v1.2.3