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

[Paul B Mahol]

Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 libavformat/Makefile     |  1 +
 libavformat/allformats.c |  1 +
 libavformat/hcom.c       | 89 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 91 insertions(+)
 create mode 100644 libavformat/hcom.c

diff --git a/libavformat/Makefile b/libavformat/Makefile
index c42ceb40c5..c010fc83f9 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -219,6 +219,7 @@ OBJS-$(CONFIG_H263_MUXER)                += rawenc.o
 OBJS-$(CONFIG_H264_DEMUXER)              += h264dec.o rawdec.o
 OBJS-$(CONFIG_H264_MUXER)                += rawenc.o
 OBJS-$(CONFIG_HASH_MUXER)                += hashenc.o
+OBJS-$(CONFIG_HCOM_DEMUXER)              += hcom.o
 OBJS-$(CONFIG_HDS_MUXER)                 += hdsenc.o
 OBJS-$(CONFIG_HEVC_DEMUXER)              += hevcdec.o rawdec.o
 OBJS-$(CONFIG_HEVC_MUXER)                += rawenc.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 399625fd78..06844986f3 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -176,6 +176,7 @@ extern AVOutputFormat ff_h263_muxer;
 extern AVInputFormat  ff_h264_demuxer;
 extern AVOutputFormat ff_h264_muxer;
 extern AVOutputFormat ff_hash_muxer;
+extern AVInputFormat  ff_hcom_demuxer;
 extern AVOutputFormat ff_hds_muxer;
 extern AVInputFormat  ff_hevc_demuxer;
 extern AVOutputFormat ff_hevc_muxer;
diff --git a/libavformat/hcom.c b/libavformat/hcom.c
new file mode 100644
index 0000000000..933ecce373
--- /dev/null
+++ b/libavformat/hcom.c
@@ -0,0 +1,89 @@
+/*
+ * HCOM demuxer
+ * Copyright (c) 2019 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 "libavcodec/internal.h"
+#include "avformat.h"
+#include "internal.h"
+#include "pcm.h"
+
+static int hcom_probe(AVProbeData *p)
+{
+    if (!memcmp(p->buf+65, "FSSD", 4) &&
+        !memcmp(p->buf+128, "HCOM", 4))
+        return AVPROBE_SCORE_MAX;
+    return 0;
+}
+
+static int hcom_read_header(AVFormatContext *s)
+{
+    AVStream *st;
+    unsigned data_size, rsrc_size, huffcount;
+    unsigned compresstype, divisor;
+    unsigned dict_entries;
+    int ret;
+
+    avio_skip(s->pb, 83);
+    data_size = avio_rb32(s->pb);
+    rsrc_size = avio_rb32(s->pb);
+    avio_skip(s->pb, 128-91+4);
+    huffcount = avio_rb32(s->pb);
+    avio_skip(s->pb, 4);
+    compresstype = avio_rb32(s->pb);
+    if (compresstype > 1)
+        return AVERROR_INVALIDDATA;
+    divisor = avio_rb32(s->pb);
+    if (divisor == 0 || divisor > 4)
+        return AVERROR_INVALIDDATA;
+    dict_entries = avio_rb16(s->pb);
+
+    st = avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+
+    st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
+    st->codecpar->channels    = 1;
+    st->codecpar->sample_rate = 22050 / divisor;
+    st->codecpar->codec_id    = AV_CODEC_ID_HCOM;
+    st->codecpar->bits_per_coded_sample = 8;
+    st->codecpar->block_align = 4;
+
+    ret = ff_alloc_extradata(st->codecpar, dict_entries * 4 + 7);
+    if (ret < 0)
+        return ret;
+    AV_WB16(st->codecpar->extradata, dict_entries);
+    AV_WB32(st->codecpar->extradata + 2, compresstype);
+    avio_read(s->pb, st->codecpar->extradata + 6, dict_entries * 4);
+    avio_skip(s->pb, 1);
+    st->codecpar->extradata[dict_entries * 4 + 6] = avio_r8(s->pb);
+
+    avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
+
+    return 0;
+}
+
+AVInputFormat ff_hcom_demuxer = {
+    .name           = "hcom",
+    .long_name      = NULL_IF_CONFIG_SMALL("Macintosh HCOM"),
+    .read_probe     = hcom_probe,
+    .read_header    = hcom_read_header,
+    .read_packet    = ff_pcm_read_packet,
+};
-- 
2.17.1