--- /dev/null
+/*
+ * MIDI Sample Dump Standard format demuxer
+ * Copyright (c) 2017 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/intreadwrite.h"
+#include "avformat.h"
+#include "internal.h"
+
+typedef struct SDSContext {
+ uint8_t data[120];
+ int bit_depth;
+ int size;
+ void (*read_block)(const uint8_t *src, uint32_t *dst);
+} SDSContext;
+
+static int sds_probe(AVProbeData *p)
+{
+ if (AV_RB32(p->buf) == 0xF07E0001 && p->buf[20] == 0xF7 &&
+ p->buf[6] >= 8 && p->buf[6] <= 28)
+ return AVPROBE_SCORE_EXTENSION;
+ return 0;
+}
+
+static void byte2_read(const uint8_t *src, uint32_t *dst)
+{
+ int i;
+
+ for (i = 0; i < 120; i += 2) {
+ unsigned sample = (src[i + 0] << 25) + (src[i + 1] << 18);
+
+ dst[i / 2] = sample;
+ }
+}
+
+static void byte3_read(const uint8_t *src, uint32_t *dst)
+{
+ int i;
+
+ for (i = 0; i < 120; i += 3) {
+ unsigned sample;
+
+ sample = (src[i + 0] << 25) | (src[i + 1] << 18) | (src[i + 2] << 11);
+ dst[i / 3] = sample;
+ }
+}
+
+static void byte4_read(const uint8_t *src, uint32_t *dst)
+{
+ int i;
+
+ for (i = 0; i < 120; i += 4) {
+ unsigned sample;
+
+ sample = (src[i + 0] << 25) | (src[i + 1] << 18) | (src[i + 2] << 11) | (src[i + 3] << 4);
+ dst[i / 4] = sample;
+ }
+}
+
+#define SDS_3BYTE_TO_INT_DECODE(x) (((x) & 0x7F) | (((x) & 0x7F00) >> 1) | (((x) & 0x7F0000) >> 2))
+
+static int sds_read_header(AVFormatContext *ctx)
+{
+ SDSContext *s = ctx->priv_data;
+ unsigned sample_period;
+ AVIOContext *pb = ctx->pb;
+ AVStream *st;
+
+ st = avformat_new_stream(ctx, NULL);
+ if (!st)
+ return AVERROR(ENOMEM);
+
+ avio_skip(pb, 4);
+ avio_skip(pb, 2);
+
+ s->bit_depth = avio_r8(pb);
+ if (s->bit_depth < 8 || s->bit_depth > 28)
+ return AVERROR_INVALIDDATA;
+
+ if (s->bit_depth < 14) {
+ s->read_block = byte2_read;
+ s->size = 60 * 4;
+ } else if (s->bit_depth < 21) {
+ s->read_block = byte3_read;
+ s->size = 40 * 4;
+ } else {
+ s->read_block = byte4_read;
+ s->size = 30 * 4;
+ }
+ st->codecpar->codec_id = AV_CODEC_ID_PCM_U32LE;
+
+ sample_period = avio_rl24(pb);
+ sample_period = SDS_3BYTE_TO_INT_DECODE(sample_period);
+ avio_skip(pb, 11);
+
+ st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
+ st->codecpar->channels = 1;
+ st->codecpar->sample_rate = sample_period ? 1000000000 / sample_period : 16000;
+ st->duration = (avio_size(pb) - 21) / (127) * s->size / 4;
+
+ avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
+
+ return 0;
+}
+
+static int sds_read_packet(AVFormatContext *ctx, AVPacket *pkt)
+{
+ SDSContext *s = ctx->priv_data;
+ AVIOContext *pb = ctx->pb;
+ int64_t pos;
+ int ret;
+
+ if (avio_feof(pb))
+ return AVERROR_EOF;
+
+ pos = avio_tell(pb);
+ if (avio_rb16(pb) != 0xF07E)
+ return AVERROR_INVALIDDATA;
+ avio_skip(pb, 3);
+
+ ret = av_new_packet(pkt, s->size);
+ if (ret < 0)
+ return ret;
+
+ ret = avio_read(pb, s->data, 120);
+
+ s->read_block(s->data, (uint32_t *)pkt->data);
+
+ avio_skip(pb, 1); // checksum
+ if (avio_r8(pb) != 0xF7)
+ return AVERROR_INVALIDDATA;
+
+ pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
+ pkt->stream_index = 0;
+ pkt->pos = pos;
+
+ return ret;
+}
+
+AVInputFormat ff_sds_demuxer = {
+ .name = "sds",
+ .long_name = NULL_IF_CONFIG_SMALL("MIDI Sample Dump Standard"),
+ .priv_data_size = sizeof(SDSContext),
+ .read_probe = sds_probe,
+ .read_header = sds_read_header,
+ .read_packet = sds_read_packet,
+ .extensions = "sds",
+ .flags = AVFMT_GENERIC_INDEX,
+};
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