[FFmpeg-devel] [PATCH 2/2] avformat: add DC STR demuxer

[Paul B Mahol]

Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 libavformat/Makefile     |  1 +
 libavformat/allformats.c |  1 +
 libavformat/dcstr.c      | 79 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 81 insertions(+)
 create mode 100644 libavformat/dcstr.c

diff --git a/libavformat/Makefile b/libavformat/Makefile
index c3d9e18..27aefcb 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -127,6 +127,7 @@ OBJS-$(CONFIG_DATA_MUXER)                += rawdec.o
 OBJS-$(CONFIG_DASH_MUXER)                += dashenc.o isom.o
 OBJS-$(CONFIG_DAUD_DEMUXER)              += dauddec.o
 OBJS-$(CONFIG_DAUD_MUXER)                += daudenc.o
+OBJS-$(CONFIG_DCSTR_DEMUXER)             += dcstr.o
 OBJS-$(CONFIG_DFA_DEMUXER)               += dfa.o
 OBJS-$(CONFIG_DIRAC_DEMUXER)             += diracdec.o rawdec.o
 OBJS-$(CONFIG_DIRAC_MUXER)               += rawenc.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index a67a226..fc42cb7 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -109,6 +109,7 @@ void av_register_all(void)
     REGISTER_MUXER   (DASH,             dash);
     REGISTER_MUXDEMUX(DATA,             data);
     REGISTER_MUXDEMUX(DAUD,             daud);
+    REGISTER_DEMUXER (DCSTR,            dcstr);
     REGISTER_DEMUXER (DFA,              dfa);
     REGISTER_MUXDEMUX(DIRAC,            dirac);
     REGISTER_MUXDEMUX(DNXHD,            dnxhd);
diff --git a/libavformat/dcstr.c b/libavformat/dcstr.c
new file mode 100644
index 0000000..1baa723
--- /dev/null
+++ b/libavformat/dcstr.c
@@ -0,0 +1,79 @@
+/*
+ * DC STR demuxer
+ * Copyright (c) 2015 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 "avformat.h"
+#include "internal.h"
+
+static int dcstr_probe(AVProbeData *p)
+{
+    if (p->buf_size < 224 || memcmp(p->buf + 213, "Sega Stream", 11))
+        return 0;
+
+    return AVPROBE_SCORE_MAX;
+}
+
+static int dcstr_read_header(AVFormatContext *s)
+{
+    unsigned codec, align;
+    AVStream *st;
+
+    st = avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+
+    st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
+    st->codec->channels    = avio_rl32(s->pb);
+    st->codec->sample_rate = avio_rl32(s->pb);
+    codec                  = avio_rl32(s->pb);
+    align                  = avio_rl32(s->pb);
+    avio_skip(s->pb, 4);
+    st->duration           = avio_rl32(s->pb);
+    st->codec->channels   *= avio_rl32(s->pb);
+    if (!align || align > INT_MAX / st->codec->channels)
+        return AVERROR_INVALIDDATA;
+    st->codec->block_align = align * st->codec->channels;
+
+    switch (codec) {
+    case  4: st->codec->codec_id = AV_CODEC_ID_ADPCM_AICA;       break;
+    case 16: st->codec->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR; break;
+    default: avpriv_request_sample(s, "codec %X", codec);
+    }
+
+    avio_skip(s->pb, 0x800 - avio_tell(s->pb));
+    avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
+
+    return 0;
+}
+
+static int dcstr_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    AVCodecContext *codec = s->streams[0]->codec;
+    return av_get_packet(s->pb, pkt, codec->block_align);
+}
+
+AVInputFormat ff_dcstr_demuxer = {
+    .name           = "dcstr",
+    .long_name      = NULL_IF_CONFIG_SMALL("Sega DC STR"),
+    .read_probe     = dcstr_probe,
+    .read_header    = dcstr_read_header,
+    .read_packet    = dcstr_read_packet,
+    .extensions     = "str",
+};
-- 
1.9.1