avformat: add Square SVS demuxer

1 files changed, 97 insertions, 0 deletions

diff --git a/libavformat/svs.c b/libavformat/svs.c
new file mode 100644
index 0000000000..d4285ed306
--- /dev/null
+++ b/libavformat/svs.c
@@ -0,0 +1,97 @@
+/*
+ * SVS demuxer
+ * Copyright (c) 2020 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"
+
+static int svs_probe(const AVProbeData *p)
+{
+    if (p->buf_size < 32)
+        return 0;
+
+    if (memcmp(p->buf, "SVS\00", 4))
+        return 0;
+
+    if (AV_RL32(p->buf + 16) == 0)
+        return 0;
+
+    return AVPROBE_SCORE_MAX / 3;
+}
+
+static int svs_read_header(AVFormatContext *s)
+{
+    AVStream *st;
+    uint32_t pitch;
+
+    st = avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+
+    avio_skip(s->pb, 16);
+    pitch = avio_rl32(s->pb);
+    avio_skip(s->pb, 12);
+
+    s->internal->data_offset     = avio_tell(s->pb);
+    st->codecpar->codec_type     = AVMEDIA_TYPE_AUDIO;
+    st->codecpar->codec_id       = AV_CODEC_ID_ADPCM_PSX;
+    st->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;
+    st->codecpar->channels       = 2;
+    st->codecpar->sample_rate    = av_rescale_rnd(pitch, 48000, 4096, AV_ROUND_INF);
+    st->codecpar->block_align    = 32;
+    st->start_time               = 0;
+    if (s->pb->seekable & AVIO_SEEKABLE_NORMAL)
+        st->duration = av_get_audio_frame_duration2(st->codecpar,
+                                                    avio_size(s->pb) - 32);
+
+    avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
+
+    return 0;
+}
+
+static int svs_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    int ret;
+
+    if (avio_feof(s->pb))
+        return AVERROR_EOF;
+
+    ret = av_get_packet(s->pb, pkt, 32 * 256);
+    if (ret != 32 * 256) {
+        if (ret < 0)
+            return ret;
+        av_shrink_packet(pkt, ret);
+        pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
+    }
+    pkt->stream_index = 0;
+
+    return ret;
+}
+
+AVInputFormat ff_svs_demuxer = {
+    .name        = "svs",
+    .long_name   = NULL_IF_CONFIG_SMALL("Square SVS"),
+    .read_probe  = svs_probe,
+    .read_header = svs_read_header,
+    .read_packet = svs_read_packet,
+    .extensions  = "svs",
+};