[FFmpeg-devel] [PATCH 1/2] avcodec: add HCOM decoder
Paul B Mahol
onemda at gmail.com
Wed Jan 2 20:53:37 EET 2019
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
libavcodec/Makefile | 1 +
libavcodec/allcodecs.c | 1 +
libavcodec/avcodec.h | 1 +
libavcodec/codec_desc.c | 7 ++
libavcodec/hcom.c | 137 ++++++++++++++++++++++++++++++++++++++++
5 files changed, 147 insertions(+)
create mode 100644 libavcodec/hcom.c
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 99799ceed2..bf746c143d 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -362,6 +362,7 @@ OBJS-$(CONFIG_H264_V4L2M2M_DECODER) += v4l2_m2m_dec.o
OBJS-$(CONFIG_H264_V4L2M2M_ENCODER) += v4l2_m2m_enc.o
OBJS-$(CONFIG_HAP_DECODER) += hapdec.o hap.o
OBJS-$(CONFIG_HAP_ENCODER) += hapenc.o hap.o
+OBJS-$(CONFIG_HCOM_DECODER) += hcom.o
OBJS-$(CONFIG_HEVC_DECODER) += hevcdec.o hevc_mvs.o \
hevc_cabac.o hevc_refs.o hevcpred.o \
hevcdsp.o hevc_filter.o hevc_data.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 4755af71b2..fe0376e27e 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -424,6 +424,7 @@ extern AVCodec ff_g723_1_decoder;
extern AVCodec ff_g729_decoder;
extern AVCodec ff_gsm_decoder;
extern AVCodec ff_gsm_ms_decoder;
+extern AVCodec ff_hcom_decoder;
extern AVCodec ff_iac_decoder;
extern AVCodec ff_ilbc_decoder;
extern AVCodec ff_imc_decoder;
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 92567ec6d0..e92d7accf4 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -646,6 +646,7 @@ enum AVCodecID {
AV_CODEC_ID_APTX_HD,
AV_CODEC_ID_SBC,
AV_CODEC_ID_ATRAC9,
+ AV_CODEC_ID_HCOM,
/* subtitle codecs */
AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index 2363a53283..10a639101c 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -2943,6 +2943,13 @@ static const AVCodecDescriptor codec_descriptors[] = {
.long_name = NULL_IF_CONFIG_SMALL("ATRAC9 (Adaptive TRansform Acoustic Coding 9)"),
.props = AV_CODEC_PROP_LOSSY,
},
+ {
+ .id = AV_CODEC_ID_HCOM,
+ .type = AVMEDIA_TYPE_AUDIO,
+ .name = "hcom",
+ .long_name = NULL_IF_CONFIG_SMALL("HCOM Audio"),
+ .props = AV_CODEC_PROP_LOSSY,
+ },
/* subtitle codecs */
{
diff --git a/libavcodec/hcom.c b/libavcodec/hcom.c
new file mode 100644
index 0000000000..e516d20a94
--- /dev/null
+++ b/libavcodec/hcom.c
@@ -0,0 +1,137 @@
+/*
+ * HCOM audio decoder
+ *
+ * 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 "avcodec.h"
+#include "bytestream.h"
+#include "internal.h"
+
+typedef struct HEntry {
+ int16_t l, r;
+} HEntry;
+
+typedef struct HCOMContext {
+ AVCodecContext *avctx;
+
+ uint8_t first_sample;
+ uint8_t sample;
+ int dict_entries;
+ int dict_entry;
+ int delta_compression;
+
+ HEntry *dict;
+} HCOMContext;
+
+static av_cold int hcom_init(AVCodecContext *avctx)
+{
+ HCOMContext *s = avctx->priv_data;
+
+ if (avctx->channels != 1) {
+ av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ if (avctx->extradata_size <= 7)
+ return AVERROR_INVALIDDATA;
+ s->dict_entries = AV_RB16(avctx->extradata);
+ if (avctx->extradata_size < s->dict_entries * 4 + 7)
+ return AVERROR_INVALIDDATA;
+ s->delta_compression = AV_RB32(avctx->extradata + 2);
+ s->sample = s->first_sample = avctx->extradata[avctx->extradata_size - 1];
+
+ s->dict = av_calloc(s->dict_entries, sizeof(*s->dict));
+ if (!s->dict)
+ return AVERROR(ENOMEM);
+ for (int i = 0; i < s->dict_entries; i++) {
+ s->dict[i].l = AV_RB16(avctx->extradata + 6 + 4 * i);
+ s->dict[i].r = AV_RB16(avctx->extradata + 6 + 4 * i + 2);
+ }
+
+ avctx->sample_fmt = AV_SAMPLE_FMT_U8;
+ s->dict_entry = 0;
+
+ return 0;
+}
+
+static int hcom_decode(AVCodecContext *avctx, void *data,
+ int *got_frame, AVPacket *pkt)
+{
+ HCOMContext *s = avctx->priv_data;
+ AVFrame *frame = data;
+ GetByteContext gb;
+ uint32_t current;
+ int ret, n = 0;
+
+ if (pkt->size > INT16_MAX)
+ return AVERROR_INVALIDDATA;
+
+ frame->nb_samples = pkt->size * 8;
+ if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+ return ret;
+
+ bytestream2_init(&gb, pkt->data, pkt->size);
+ while (bytestream2_get_bytes_left(&gb) >= 4) {
+ int bits = 32;
+
+ current = bytestream2_get_be32(&gb);
+
+ while (bits-- > 0) {
+
+ if (current & 0x80000000) {
+ s->dict_entry = s->dict[s->dict_entry].r;
+ } else {
+ s->dict_entry = s->dict[s->dict_entry].l;
+ }
+
+ current = current << 1;
+ if (s->dict[s->dict_entry].l < 0) {
+ int16_t datum;
+
+ datum = s->dict[s->dict_entry].r;
+
+ if (!s->delta_compression)
+ s->sample = 0;
+ s->sample = (s->sample + datum) & 0xFF;
+
+ frame->data[0][n++] = s->sample;
+
+ s->dict_entry = 0;
+ }
+ }
+ }
+
+ frame->nb_samples = n;
+
+ *got_frame = 1;
+
+ return pkt->size;
+}
+
+AVCodec ff_hcom_decoder = {
+ .name = "hcom",
+ .long_name = NULL_IF_CONFIG_SMALL("HCOM Audio"),
+ .type = AVMEDIA_TYPE_AUDIO,
+ .id = AV_CODEC_ID_HCOM,
+ .priv_data_size = sizeof(HCOMContext),
+ .init = hcom_init,
+ .decode = hcom_decode,
+ .capabilities = AV_CODEC_CAP_DR1,
+};
--
2.17.1
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