[FFmpeg-cvslog] avcodec: add MI-SC4 audio decoder
Paul B Mahol
git at videolan.org
Fri Sep 16 11:01:44 EEST 2022
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Thu Sep 8 20:44:49 2022 +0200| [ea93943bee2efbfc44417eccdac712c5d9d677ec] | committer: Paul B Mahol
avcodec: add MI-SC4 audio decoder
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ea93943bee2efbfc44417eccdac712c5d9d677ec
---
Changelog | 1 +
doc/general_contents.texi | 1 +
libavcodec/Makefile | 1 +
libavcodec/allcodecs.c | 1 +
libavcodec/codec_desc.c | 7 ++
libavcodec/codec_id.h | 1 +
libavcodec/misc4.c | 186 ++++++++++++++++++++++++++++++++++++++++++++++
libavcodec/version.h | 2 +-
libavformat/riff.c | 1 +
9 files changed, 200 insertions(+), 1 deletion(-)
diff --git a/Changelog b/Changelog
index f76fce36b8..9e1f705539 100644
--- a/Changelog
+++ b/Changelog
@@ -12,6 +12,7 @@ version <next>:
- WBMP (Wireless Application Protocol Bitmap) image format
- a3dscope filter
- bonk decoder and demuxer
+- Micronas SC-4 audio decoder
version 5.1:
diff --git a/doc/general_contents.texi b/doc/general_contents.texi
index 86ec6d606b..150b7944a8 100644
--- a/doc/general_contents.texi
+++ b/doc/general_contents.texi
@@ -1256,6 +1256,7 @@ following image formats are supported:
@item Interplay ACM @tab @tab X
@item MACE (Macintosh Audio Compression/Expansion) 3:1 @tab @tab X
@item MACE (Macintosh Audio Compression/Expansion) 6:1 @tab @tab X
+ at item MI-SC4 (Micronas SC-4 Audio) @tab @tab X
@item MLP (Meridian Lossless Packing) @tab X @tab X
@tab Used in DVD-Audio discs.
@item Monkey's Audio @tab @tab X
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 0b46bc0173..4112a0fb2e 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -471,6 +471,7 @@ OBJS-$(CONFIG_METASOUND_DECODER) += metasound.o metasound_data.o \
twinvq.o
OBJS-$(CONFIG_MICRODVD_DECODER) += microdvddec.o ass.o
OBJS-$(CONFIG_MIMIC_DECODER) += mimic.o
+OBJS-$(CONFIG_MISC4_DECODER) += misc4.o
OBJS-$(CONFIG_MJPEG_DECODER) += mjpegdec.o mjpegdec_common.o
OBJS-$(CONFIG_MJPEG_QSV_DECODER) += qsvdec.o
OBJS-$(CONFIG_MJPEG_ENCODER) += mjpegenc.o mjpegenc_common.o \
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 5d58a5d9f0..447225e26b 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -483,6 +483,7 @@ extern const FFCodec ff_interplay_acm_decoder;
extern const FFCodec ff_mace3_decoder;
extern const FFCodec ff_mace6_decoder;
extern const FFCodec ff_metasound_decoder;
+extern const FFCodec ff_misc4_decoder;
extern const FFCodec ff_mlp_encoder;
extern const FFCodec ff_mlp_decoder;
extern const FFCodec ff_mp1_decoder;
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index c002480d39..648c518b3c 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -3297,6 +3297,13 @@ static const AVCodecDescriptor codec_descriptors[] = {
.long_name = NULL_IF_CONFIG_SMALL("Bonk audio"),
.props = AV_CODEC_PROP_LOSSY | AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSLESS,
},
+ {
+ .id = AV_CODEC_ID_MISC4,
+ .type = AVMEDIA_TYPE_AUDIO,
+ .name = "misc4",
+ .long_name = NULL_IF_CONFIG_SMALL("Micronas SC-4 Audio"),
+ .props = AV_CODEC_PROP_LOSSY | AV_CODEC_PROP_INTRA_ONLY,
+ },
/* subtitle codecs */
{
diff --git a/libavcodec/codec_id.h b/libavcodec/codec_id.h
index 858b5c3a75..bc8226ff07 100644
--- a/libavcodec/codec_id.h
+++ b/libavcodec/codec_id.h
@@ -528,6 +528,7 @@ enum AVCodecID {
AV_CODEC_ID_MSNSIREN,
AV_CODEC_ID_DFPWM,
AV_CODEC_ID_BONK,
+ AV_CODEC_ID_MISC4,
/* subtitle codecs */
AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
diff --git a/libavcodec/misc4.c b/libavcodec/misc4.c
new file mode 100644
index 0000000000..1bf162e120
--- /dev/null
+++ b/libavcodec/misc4.c
@@ -0,0 +1,186 @@
+/*
+ * Micronas SC-4 audio decoder
+ * Copyright (c) 2022 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/internal.h"
+#include "libavutil/intreadwrite.h"
+#include "avcodec.h"
+#include "codec_internal.h"
+#include "decode.h"
+#include "bytestream.h"
+#include "mathops.h"
+
+static const int16_t steps[16] = {
+ 4084, 18, 41, 64, 112, 198, 355, 1122,
+ 1122, 355, 198, 112, 64, 41, 18, 4084,
+};
+
+static const int16_t diffs[16] = {
+ 2048, 4, 135, 213, 273, 323, 373, 425,
+ 425, 373, 323, 273, 213, 135, 4, 2048,
+};
+
+typedef struct ChannelContext {
+ unsigned last_step;
+ int64_t new_pred;
+ int64_t pred;
+ int64_t weights_tab[6];
+ int32_t diffs_tab[6];
+} ChannelContext;
+
+typedef struct MISC4Context {
+ GetByteContext gb;
+
+ uint32_t marker;
+
+ ChannelContext ch[2];
+} MISC4Context;
+
+static av_cold int misc4_init(AVCodecContext *avctx)
+{
+ MISC4Context *s = avctx->priv_data;
+
+ avctx->sample_fmt = AV_SAMPLE_FMT_S16;
+ switch (avctx->sample_rate) {
+ case 8000:
+ case 11025:
+ s->marker = 0x11b;
+ break;
+ case 16000:
+ case 32000:
+ s->marker = 0x2b2;
+ break;
+ }
+
+ return 0;
+}
+
+#define FRACBITS 12
+#define WEIGHTSBITS 26
+
+static int64_t prediction(int delta, ChannelContext *c)
+{
+ const int isign = FFDIFFSIGN(delta, 0);
+ int64_t dotpr = 0;
+
+ c->new_pred = delta * (1LL << FRACBITS) + c->pred;
+
+ for (int i = 0; i < 6; i++) {
+ const int sign = FFSIGN(c->diffs_tab[i]);
+ c->weights_tab[i] = (c->weights_tab[i] * 255LL) / 256;
+ c->weights_tab[i] += (1LL << (WEIGHTSBITS + 1)) * sign * isign;
+ }
+
+ memmove(&c->diffs_tab[1], &c->diffs_tab[0], 5 * sizeof(int32_t));
+
+ c->diffs_tab[0] = -delta * (1 << (FRACBITS-8));
+ c->pred = c->new_pred;
+
+ dotpr = 0;
+ for (int i = 0; i < 6; i++)
+ dotpr += ((int64_t)c->diffs_tab[i] * c->weights_tab[i]) >> WEIGHTSBITS;
+
+ c->pred += dotpr;
+ c->pred = av_clip64(c->pred, -16383 * (1 << FRACBITS), 16383 * (1 << FRACBITS));
+ c->pred = c->pred * 9 / 10;
+
+ return c->new_pred;
+}
+
+static int16_t decode(ChannelContext *c, unsigned nibble)
+{
+ int diff, diff_sign, adiff = 0, delta;
+ uint32_t step, newstep;
+ int64_t pred;
+
+ diff_sign = nibble >> 3;
+ diff = diffs[nibble];
+ step = diff + (c->last_step >> 2);
+ newstep = step & 0xfff;
+ if (newstep >> 11 == 0)
+ adiff = (((step & 0x7f) + 0x80) * 128) >>
+ (14 - (newstep >> 7));
+ delta = diff_sign ? -adiff : adiff;
+ delta = av_clip_intp2(delta, 15);
+ pred = prediction(delta, c);
+ nibble = steps[nibble];
+ newstep = nibble * 32 - c->last_step & 0x1ffff;
+ newstep = ((newstep >> 5) + (newstep & 0x10000 ? 0x1000 : 0) + c->last_step) & 0x1fff;
+ c->last_step = av_clip(newstep, 544, 5120);
+
+ return av_clip_int16(pred >> (FRACBITS - 3));
+}
+
+static int misc4_decode(AVCodecContext *avctx, AVFrame *frame,
+ int *got_frame_ptr, AVPacket *pkt)
+{
+ MISC4Context *s = avctx->priv_data;
+ GetByteContext *gb = &s->gb;
+ uint32_t hdr;
+ int ret;
+
+ bytestream2_init(gb, pkt->data, pkt->size);
+
+ frame->nb_samples = 29 * (1 + (avctx->ch_layout.nb_channels == 1));
+ if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+ return ret;
+
+ hdr = bytestream2_peek_be32(gb);
+ if (hdr == s->marker) {
+ bytestream2_skip(gb, 5);
+ } else if ((hdr >> 16) == s->marker) {
+ bytestream2_skip(gb, 3);
+ }
+
+ {
+ int16_t *samples = (int16_t *)frame->data[0];
+ const int st = avctx->ch_layout.nb_channels == 2;
+ int n;
+
+ for (n = 0; n < 29; n++) {
+ int nibble = bytestream2_get_byte(gb);
+ samples[2*n+0] = decode(&s->ch[0 ], nibble >> 4);
+ samples[2*n+1] = decode(&s->ch[st], nibble & 15);
+ if (bytestream2_get_bytes_left(gb) <= 0)
+ break;
+ }
+
+ if (n == 29 && bytestream2_get_byte(gb) != 0x55)
+ return AVERROR_INVALIDDATA;
+ }
+
+ *got_frame_ptr = 1;
+
+ return bytestream2_tell(gb);
+}
+
+const FFCodec ff_misc4_decoder = {
+ .p.name = "misc4",
+ CODEC_LONG_NAME("Micronas SC-4 Audio"),
+ .p.type = AVMEDIA_TYPE_AUDIO,
+ .p.id = AV_CODEC_ID_MISC4,
+ .priv_data_size = sizeof(MISC4Context),
+ .init = misc4_init,
+ FF_CODEC_DECODE_CB(misc4_decode),
+ .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_SUBFRAMES |
+ AV_CODEC_CAP_CHANNEL_CONF,
+ .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16,
+ AV_SAMPLE_FMT_NONE },
+};
diff --git a/libavcodec/version.h b/libavcodec/version.h
index 2328be4b26..2cad78e640 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -29,7 +29,7 @@
#include "version_major.h"
-#define LIBAVCODEC_VERSION_MINOR 43
+#define LIBAVCODEC_VERSION_MINOR 44
#define LIBAVCODEC_VERSION_MICRO 100
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
diff --git a/libavformat/riff.c b/libavformat/riff.c
index 6c06ad2d60..5114114364 100644
--- a/libavformat/riff.c
+++ b/libavformat/riff.c
@@ -564,6 +564,7 @@ const AVCodecTag ff_codec_wav_tags[] = {
{ AV_CODEC_ID_ATRAC3, 0x0270 },
{ AV_CODEC_ID_MSNSIREN, 0x028E },
{ AV_CODEC_ID_ADPCM_G722, 0x028F },
+ { AV_CODEC_ID_MISC4, 0x0350 },
{ AV_CODEC_ID_IMC, 0x0401 },
{ AV_CODEC_ID_IAC, 0x0402 },
{ AV_CODEC_ID_ON2AVC, 0x0500 },
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