[FFmpeg-devel] [PATCH 2/2] avformat: add demuxer for Simon & Schuster Interactive's VAG format
Zane van Iperen
zane at zanevaniperen.com
Sat Feb 1 06:12:42 EET 2020
Adds support for the custom VAG container used by some Simon & Schuster
Interactive games such as Real War, and Real War: Rogue States.
Signed-off-by: Zane van Iperen <zane at zanevaniperen.com>
---
libavformat/Makefile | 1 +
libavformat/allformats.c | 1 +
libavformat/kvag.c | 149 +++++++++++++++++++++++++++++++++++++++
libavformat/version.h | 2 +-
4 files changed, 152 insertions(+), 1 deletion(-)
create mode 100644 libavformat/kvag.c
diff --git a/libavformat/Makefile b/libavformat/Makefile
index ba6ea8c4a6..710cc4d088 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -279,6 +279,7 @@ OBJS-$(CONFIG_JACOSUB_DEMUXER) += jacosubdec.o subtitles.o
OBJS-$(CONFIG_JACOSUB_MUXER) += jacosubenc.o rawenc.o
OBJS-$(CONFIG_JV_DEMUXER) += jvdec.o
OBJS-$(CONFIG_KUX_DEMUXER) += flvdec.o
+OBJS-$(CONFIG_KVAG_DEMUXER) += kvag.o
OBJS-$(CONFIG_LATM_MUXER) += latmenc.o rawenc.o
OBJS-$(CONFIG_LMLM4_DEMUXER) += lmlm4.o
OBJS-$(CONFIG_LOAS_DEMUXER) += loasdec.o rawdec.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index fe74a32e47..3ea4100e85 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -214,6 +214,7 @@ extern AVInputFormat ff_jacosub_demuxer;
extern AVOutputFormat ff_jacosub_muxer;
extern AVInputFormat ff_jv_demuxer;
extern AVInputFormat ff_kux_demuxer;
+extern AVInputFormat ff_kvag_demuxer;
extern AVOutputFormat ff_latm_muxer;
extern AVInputFormat ff_lmlm4_demuxer;
extern AVInputFormat ff_loas_demuxer;
diff --git a/libavformat/kvag.c b/libavformat/kvag.c
new file mode 100644
index 0000000000..fb58701fd7
--- /dev/null
+++ b/libavformat/kvag.c
@@ -0,0 +1,149 @@
+/*
+ * Simon & Schuster Interactive VAG demuxer
+ *
+ * Copyright (C) 2020 Zane van Iperen (zane at zanevaniperen.com)
+ *
+ * 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 "avformat.h"
+#include "internal.h"
+#include "libavutil/intreadwrite.h"
+
+#define KVAG_TAG MKTAG('K', 'V', 'A', 'G')
+#define KVAG_HEADER_SIZE 14
+
+typedef struct KVAGHeader {
+ uint32_t magic;
+ uint32_t data_size;
+ uint32_t sample_rate;
+ uint32_t stereo;
+} KVAGHeader;
+
+typedef struct KVAGDemuxContext {
+ KVAGHeader hdr;
+ uint32_t samples_per_frame;
+ uint32_t bytes_read;
+} KVAGDemuxContext;
+
+static int kvag_probe(const AVProbeData *p)
+{
+ if (AV_RL32(p->buf) != KVAG_TAG)
+ return 0;
+
+ return AVPROBE_SCORE_EXTENSION + 1;
+}
+
+static int kvag_read_header(AVFormatContext *s)
+{
+ int64_t ret;
+ AVIOContext *pb = s->pb;
+ AVStream *st;
+ KVAGDemuxContext *kvag = s->priv_data;
+
+ uint8_t buf[KVAG_HEADER_SIZE];
+
+ if (!(st = avformat_new_stream(s, NULL)))
+ return AVERROR(ENOMEM);
+
+ if ((ret = avio_read(pb, buf, KVAG_HEADER_SIZE)) < 0)
+ return ret;
+ else if (ret != KVAG_HEADER_SIZE)
+ return AVERROR(EIO);
+
+ kvag->hdr.magic = AV_RL32(buf + 0);
+ kvag->hdr.data_size = AV_RL32(buf + 4);
+ kvag->hdr.sample_rate = AV_RL32(buf + 8);
+ kvag->hdr.stereo = AV_RL16(buf + 12);
+
+
+ st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
+ st->codecpar->codec_id = AV_CODEC_ID_ADPCM_IMA_SSI;
+ st->codecpar->format = AV_SAMPLE_FMT_S16;
+
+ if (kvag->hdr.stereo) {
+ st->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;
+ st->codecpar->channels = 2;
+ } else {
+ st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
+ st->codecpar->channels = 1;
+ }
+
+ st->codecpar->sample_rate = kvag->hdr.sample_rate;
+ st->codecpar->bits_per_coded_sample = 4;
+ st->codecpar->bits_per_raw_sample = 16;
+
+ /*
+ * The game doesn't use "frames", it just reads the whole file.
+ * 32 seems like a good number.
+ */
+ st->codecpar->frame_size = 32;
+ st->codecpar->block_align = st->codecpar->frame_size;
+ st->codecpar->bit_rate = st->codecpar->channels *
+ st->codecpar->sample_rate *
+ st->codecpar->bits_per_coded_sample;
+
+ avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
+ st->start_time = 0;
+ st->nb_frames = ROUNDED_DIV(kvag->hdr.data_size, st->codecpar->frame_size);
+
+ kvag->samples_per_frame = st->codecpar->frame_size *
+ (8 / st->codecpar->bits_per_coded_sample) /
+ st->codecpar->channels;
+
+ st->duration = st->nb_frames * kvag->samples_per_frame;
+ return 0;
+}
+
+static int kvag_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+ int ret;
+ AVStream *st = s->streams[0];
+ KVAGDemuxContext *kvag = s->priv_data;
+
+ if (kvag->bytes_read >= kvag->hdr.data_size) {
+ return AVERROR_EOF;
+ }
+
+ if ((ret = av_get_packet(s->pb, pkt, st->codecpar->frame_size)) < 0) {
+ return ret;
+ } else if (ret < st->codecpar->frame_size) {
+ if (!avio_feof(s->pb)) {
+ return AVERROR_INVALIDDATA;
+ }
+
+ /*
+ * In some files, the actual size is less than the data size. The game
+ * just overreads the buffer. A truncated final "frame" is fine.
+ */
+ pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
+ }
+
+ pkt->stream_index = st->index;
+ pkt->duration = kvag->samples_per_frame;
+
+ kvag->bytes_read += ret;
+ return 0;
+}
+
+AVInputFormat ff_kvag_demuxer = {
+ .name = "kvag",
+ .long_name = NULL_IF_CONFIG_SMALL("Simon & Schuster Interactive VAG"),
+ .priv_data_size = sizeof(KVAGDemuxContext),
+ .read_probe = kvag_probe,
+ .read_header = kvag_read_header,
+ .read_packet = kvag_read_packet
+};
diff --git a/libavformat/version.h b/libavformat/version.h
index 15fdb73e3e..be22abc010 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -32,7 +32,7 @@
// Major bumping may affect Ticket5467, 5421, 5451(compatibility with Chromium)
// Also please add any ticket numbers that you believe might be affected here
#define LIBAVFORMAT_VERSION_MAJOR 58
-#define LIBAVFORMAT_VERSION_MINOR 37
+#define LIBAVFORMAT_VERSION_MINOR 38
#define LIBAVFORMAT_VERSION_MICRO 100
#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
--
2.17.1
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