[FFmpeg-devel] [PATCH] avformat: add tri-ACE demuxer

[Paul B Mahol]

Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 libavformat/Makefile     |   1 +
 libavformat/acedec.c     | 114 +++++++++++++++++++++++++++++++++++++++
 libavformat/allformats.c |   1 +
 3 files changed, 116 insertions(+)
 create mode 100644 libavformat/acedec.c

diff --git a/libavformat/Makefile b/libavformat/Makefile
index 213004cb45..e82af409b7 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -71,6 +71,7 @@ OBJS-$(CONFIG_AAC_DEMUXER)               += aacdec.o apetag.o img2.o rawdec.o
 OBJS-$(CONFIG_AAX_DEMUXER)               += aaxdec.o
 OBJS-$(CONFIG_AC3_DEMUXER)               += ac3dec.o rawdec.o
 OBJS-$(CONFIG_AC3_MUXER)                 += rawenc.o
+OBJS-$(CONFIG_ACE_DEMUXER)               += acedec.o
 OBJS-$(CONFIG_ACM_DEMUXER)               += acm.o rawdec.o
 OBJS-$(CONFIG_ACT_DEMUXER)               += act.o
 OBJS-$(CONFIG_ADF_DEMUXER)               += bintext.o sauce.o
diff --git a/libavformat/acedec.c b/libavformat/acedec.c
new file mode 100644
index 0000000000..c6d0c33e52
--- /dev/null
+++ b/libavformat/acedec.c
@@ -0,0 +1,114 @@
+/*
+ * ACE 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/intreadwrite.h"
+#include "avformat.h"
+#include "internal.h"
+
+static int ace_probe(const AVProbeData *p)
+{
+    uint32_t asc;
+
+    if (AV_RB32(p->buf) != MKBETAG('A','A','C',' '))
+        return 0;
+    if (p->buf_size < 0x44)
+        return 0;
+    asc = AV_RB32(p->buf + 0x40);
+    if (asc < 0x44 || asc > p->buf_size - 4)
+        return 0;
+    if (AV_RB32(p->buf + asc) != MKBETAG('A','S','C',' '))
+        return 0;
+
+    return AVPROBE_SCORE_MAX / 2 + 1;
+}
+
+static int ace_read_header(AVFormatContext *s)
+{
+    AVIOContext *pb = s->pb;
+    AVCodecParameters *par;
+    int ret, codec, rate, nb_channels;
+    uint32_t asc_pos, size;
+    AVStream *st;
+
+    avio_skip(pb, 0x40);
+    asc_pos = avio_rb32(pb);
+    if (asc_pos < 0x44)
+        return AVERROR_INVALIDDATA;
+    avio_skip(pb, asc_pos - 0x44);
+    if (avio_rb32(pb) != MKBETAG('A','S','C',' '))
+        return AVERROR_INVALIDDATA;
+    avio_skip(pb, 0xec);
+    codec = avio_rb32(pb);
+    nb_channels = avio_rb32(pb);
+    if (nb_channels <= 0 || nb_channels > INT32_MAX / 256)
+        return AVERROR_INVALIDDATA;
+    size = avio_rb32(pb);
+    if (size == 0)
+        return AVERROR_INVALIDDATA;
+    rate = avio_rb32(pb);
+    if (rate <= 0)
+        return AVERROR_INVALIDDATA;
+    avio_skip(pb, 16);
+
+    st = avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+    st->start_time = 0;
+    par = st->codecpar;
+    par->codec_type  = AVMEDIA_TYPE_AUDIO;
+    par->channels    = nb_channels;
+    par->sample_rate = rate;
+    par->block_align = (codec == 4 ? 0x60 : codec == 5 ? 0x98 : 0xC0) * nb_channels;
+    st->duration     = (size / par->block_align) * 1024LL;
+    par->codec_id    = AV_CODEC_ID_ATRAC3;
+
+    ret = ff_alloc_extradata(par, 14);
+    if (ret < 0)
+        return ret;
+
+    AV_WL16(st->codecpar->extradata, 1);
+    AV_WL16(st->codecpar->extradata+2, 2048 * par->channels);
+    AV_WL16(st->codecpar->extradata+4, 0);
+    AV_WL16(st->codecpar->extradata+6, codec == 4 ? 1 : 0);
+    AV_WL16(st->codecpar->extradata+8, codec == 4 ? 1 : 0);
+    AV_WL16(st->codecpar->extradata+10, 1);
+    AV_WL16(st->codecpar->extradata+12, 0);
+
+    avpriv_set_pts_info(st, 64, 1, par->sample_rate);
+
+    return 0;
+}
+
+static int ace_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    AVCodecParameters *par = s->streams[0]->codecpar;
+
+    return av_get_packet(s->pb, pkt, par->block_align ? par->block_align : 1024 * par->channels);
+}
+
+AVInputFormat ff_ace_demuxer = {
+    .name           = "ace",
+    .long_name      = NULL_IF_CONFIG_SMALL("tri-Ace Audio Container"),
+    .read_probe     = ace_probe,
+    .read_header    = ace_read_header,
+    .read_packet    = ace_read_packet,
+    .flags          = AVFMT_GENERIC_INDEX,
+};
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 3a6b8e6dac..9d85b8ccc3 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -34,6 +34,7 @@ extern AVInputFormat  ff_aac_demuxer;
 extern AVInputFormat  ff_aax_demuxer;
 extern AVInputFormat  ff_ac3_demuxer;
 extern AVOutputFormat ff_ac3_muxer;
+extern AVInputFormat  ff_ace_demuxer;
 extern AVInputFormat  ff_acm_demuxer;
 extern AVInputFormat  ff_act_demuxer;
 extern AVInputFormat  ff_adf_demuxer;
-- 
2.17.1