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-rw-r--r--libavformat/astdec.c119
1 files changed, 119 insertions, 0 deletions
diff --git a/libavformat/astdec.c b/libavformat/astdec.c
new file mode 100644
index 0000000000..fb5a34fddd
--- /dev/null
+++ b/libavformat/astdec.c
@@ -0,0 +1,119 @@
+/*
+ * AST demuxer
+ * Copyright (c) 2012 Paul B Mahol
+ *
+ * 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 "libavutil/channel_layout.h"
+#include "libavutil/intreadwrite.h"
+#include "avformat.h"
+#include "internal.h"
+#include "ast.h"
+
+static int ast_probe(AVProbeData *p)
+{
+ if (AV_RL32(p->buf) == MKTAG('S','T','R','M') &&
+ AV_RB16(p->buf + 10) &&
+ AV_RB16(p->buf + 12) &&
+ AV_RB32(p->buf + 16))
+ return AVPROBE_SCORE_MAX / 3 * 2;
+ return 0;
+}
+
+static int ast_read_header(AVFormatContext *s)
+{
+ int depth;
+ AVStream *st;
+
+ st = avformat_new_stream(s, NULL);
+ if (!st)
+ return AVERROR(ENOMEM);
+
+ avio_skip(s->pb, 8);
+ st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
+ st->codec->codec_id = ff_codec_get_id(ff_codec_ast_tags, avio_rb16(s->pb));
+
+ depth = avio_rb16(s->pb);
+ if (depth != 16) {
+ av_log_ask_for_sample(s, "unsupported depth %d\n", depth);
+ return AVERROR_INVALIDDATA;
+ }
+
+ st->codec->channels = avio_rb16(s->pb);
+ if (!st->codec->channels)
+ return AVERROR_INVALIDDATA;
+
+ if (st->codec->channels == 2)
+ st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
+ else if (st->codec->channels == 4)
+ st->codec->channel_layout = AV_CH_LAYOUT_4POINT0;
+
+ avio_skip(s->pb, 2);
+ st->codec->sample_rate = avio_rb32(s->pb);
+ if (st->codec->sample_rate <= 0)
+ return AVERROR_INVALIDDATA;
+ st->start_time = 0;
+ st->duration = avio_rb32(s->pb);
+ avio_skip(s->pb, 40);
+ avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
+
+ return 0;
+}
+
+static int ast_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+ uint32_t type, size;
+ int64_t pos;
+ int ret;
+
+ if (url_feof(s->pb))
+ return AVERROR_EOF;
+
+ pos = avio_tell(s->pb);
+ type = avio_rl32(s->pb);
+ size = avio_rb32(s->pb);
+ if (size > INT_MAX / s->streams[0]->codec->channels)
+ return AVERROR_INVALIDDATA;
+
+ size *= s->streams[0]->codec->channels;
+ if ((ret = avio_skip(s->pb, 24)) < 0) // padding
+ return ret;
+
+ if (type == MKTAG('B','L','C','K')) {
+ ret = av_get_packet(s->pb, pkt, size);
+ pkt->stream_index = 0;
+ pkt->pos = pos;
+ } else {
+ av_log(s, AV_LOG_ERROR, "unknown chunk %x\n", type);
+ avio_skip(s->pb, size);
+ ret = AVERROR_INVALIDDATA;
+ }
+
+ return ret;
+}
+
+AVInputFormat ff_ast_demuxer = {
+ .name = "ast",
+ .long_name = NULL_IF_CONFIG_SMALL("AST (Audio Stream)"),
+ .read_probe = ast_probe,
+ .read_header = ast_read_header,
+ .read_packet = ast_read_packet,
+ .extensions = "ast",
+ .flags = AVFMT_GENERIC_INDEX,
+ .codec_tag = (const AVCodecTag* const []){ff_codec_ast_tags, 0},
+};