mirror of
https://github.com/librempeg/librempeg
synced 2024-11-23 03:28:27 +00:00
111 lines
3.2 KiB
C
111 lines
3.2 KiB
C
/*
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* Adobe Filmstrip demuxer
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* Copyright (c) 2010 Peter Ross
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*
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* This file is part of Libav.
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*
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* Libav is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* Libav is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with Libav; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* Adobe Filmstrip demuxer
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*/
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#include "libavutil/intreadwrite.h"
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#include "avformat.h"
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#include "internal.h"
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#define RAND_TAG MKBETAG('R','a','n','d')
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typedef struct {
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int leading;
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} FilmstripDemuxContext;
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static int read_header(AVFormatContext *s,
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AVFormatParameters *ap)
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{
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FilmstripDemuxContext *film = s->priv_data;
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AVIOContext *pb = s->pb;
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AVStream *st;
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if (!s->pb->seekable)
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return AVERROR(EIO);
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avio_seek(pb, avio_size(pb) - 36, SEEK_SET);
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if (avio_rb32(pb) != RAND_TAG) {
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av_log(s, AV_LOG_ERROR, "magic number not found");
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return AVERROR_INVALIDDATA;
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}
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st = avformat_new_stream(s, NULL);
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if (!st)
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return AVERROR(ENOMEM);
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st->nb_frames = avio_rb32(pb);
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if (avio_rb16(pb) != 0) {
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av_log_ask_for_sample(s, "unsupported packing method\n");
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return AVERROR_INVALIDDATA;
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}
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avio_skip(pb, 2);
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st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
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st->codec->codec_id = CODEC_ID_RAWVIDEO;
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st->codec->pix_fmt = PIX_FMT_RGBA;
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st->codec->codec_tag = 0; /* no fourcc */
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st->codec->width = avio_rb16(pb);
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st->codec->height = avio_rb16(pb);
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film->leading = avio_rb16(pb);
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avpriv_set_pts_info(st, 64, 1, avio_rb16(pb));
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avio_seek(pb, 0, SEEK_SET);
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return 0;
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}
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static int read_packet(AVFormatContext *s,
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AVPacket *pkt)
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{
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FilmstripDemuxContext *film = s->priv_data;
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AVStream *st = s->streams[0];
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if (s->pb->eof_reached)
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return AVERROR(EIO);
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pkt->dts = avio_tell(s->pb) / (st->codec->width * (st->codec->height + film->leading) * 4);
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pkt->size = av_get_packet(s->pb, pkt, st->codec->width * st->codec->height * 4);
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avio_skip(s->pb, st->codec->width * film->leading * 4);
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if (pkt->size < 0)
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return pkt->size;
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pkt->flags |= AV_PKT_FLAG_KEY;
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return 0;
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}
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static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
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{
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AVStream *st = s->streams[stream_index];
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avio_seek(s->pb, FFMAX(timestamp, 0) * st->codec->width * st->codec->height * 4, SEEK_SET);
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return 0;
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}
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AVInputFormat ff_filmstrip_demuxer = {
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.name = "filmstrip",
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.long_name = NULL_IF_CONFIG_SMALL("Adobe Filmstrip"),
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.priv_data_size = sizeof(FilmstripDemuxContext),
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.read_header = read_header,
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.read_packet = read_packet,
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.read_seek = read_seek,
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.extensions = "flm",
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};
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