[FFmpeg-devel] [PATCH 2/2] avformat: add kvag muxer

[Zane van Iperen]

Signed-off-by: Zane van Iperen <zane at zanevaniperen.com>
---
 Changelog                |  1 +
 libavformat/Makefile     |  1 +
 libavformat/allformats.c |  1 +
 libavformat/kvag.c       | 78 +++++++++++++++++++++++++++++++++++++++-
 libavformat/version.h    |  2 +-
 5 files changed, 81 insertions(+), 2 deletions(-)

diff --git a/Changelog b/Changelog
index b4fff44329..b2de88484b 100644
--- a/Changelog
+++ b/Changelog
@@ -57,6 +57,7 @@ version <next>:
 - overlay_cuda filter
 - switch from AvxSynth to AviSynth+ on Linux
 - Simon & Schuster Interactive ADPCM encoder
+- Real War KVAG muxer
 
 
 version 4.2:
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 8fd0d43721..ff920c4373 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -285,6 +285,7 @@ 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-$(CONFIG_KVAG_MUXER)                += kvag.o
 OBJS-$(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 39d2c352f5..e12b50375c 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -220,6 +220,7 @@ extern AVOutputFormat ff_jacosub_muxer;
 extern AVInputFormat  ff_jv_demuxer;
 extern AVInputFormat  ff_kux_demuxer;
 extern AVInputFormat  ff_kvag_demuxer;
+extern AVOutputFormat ff_kvag_muxer;
 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
index 71b0eb4118..d337d1cd4f 100644
--- a/libavformat/kvag.c
+++ b/libavformat/kvag.c
@@ -1,5 +1,5 @@
 /*
- * Simon & Schuster Interactive VAG demuxer
+ * Simon & Schuster Interactive VAG (de)muxer
  *
  * Copyright (C) 2020 Zane van Iperen (zane at zanevaniperen.com)
  *
@@ -34,6 +34,7 @@ typedef struct KVAGHeader {
     uint16_t    stereo;
 } KVAGHeader;
 
+#if CONFIG_KVAG_DEMUXER
 static int kvag_probe(const AVProbeData *p)
 {
     if (AV_RL32(p->buf) != KVAG_TAG)
@@ -115,3 +116,78 @@ AVInputFormat ff_kvag_demuxer = {
     .read_header    = kvag_read_header,
     .read_packet    = kvag_read_packet
 };
+#endif
+
+#if CONFIG_KVAG_MUXER
+static int kvag_write_header(AVFormatContext *s)
+{
+    AVCodecParameters *par;
+    uint8_t buf[KVAG_HEADER_SIZE];
+
+    if (s->nb_streams != 1) {
+        av_log(s, AV_LOG_ERROR, "KVAG files have exactly one stream\n");
+        return AVERROR(EINVAL);
+    }
+
+    par = s->streams[0]->codecpar;
+
+    if (par->codec_id != AV_CODEC_ID_ADPCM_IMA_SSI) {
+        AVCodec *codec = avcodec_find_encoder(par->codec_id);
+        av_log(s, AV_LOG_ERROR, "%s codec not supported\n",
+               codec ? codec->name : "NONE");
+        return AVERROR(EINVAL);
+    }
+
+    if (par->channels > 2) {
+        av_log(s, AV_LOG_ERROR, "KVAG files only support up to 2 channels\n");
+        return AVERROR(EINVAL);
+    }
+
+    AV_WL32(buf +  0, KVAG_TAG);
+    AV_WL32(buf +  4, 0); /* Data size, we fix this up later. */
+    AV_WL32(buf +  8, par->sample_rate);
+    AV_WL16(buf + 12, par->channels == 2);
+
+    avio_write(s->pb, buf, sizeof(buf));
+    return 0;
+}
+
+static int kvag_write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    avio_write(s->pb, pkt->data, pkt->size);
+    return 0;
+}
+
+static int kvag_write_trailer(AVFormatContext *s)
+{
+    int64_t file_size, data_size;
+
+    if (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL))
+        return 0;
+
+    file_size = avio_tell(s->pb);
+    data_size = file_size - KVAG_HEADER_SIZE;
+    if (data_size < UINT32_MAX) {
+        avio_seek(s->pb, 4, SEEK_SET);
+        avio_wl32(s->pb, (uint32_t)data_size);
+        avio_seek(s->pb, file_size, SEEK_SET);
+    } else {
+        av_log(s, AV_LOG_ERROR,
+               "Filesize %"PRId64" invalid for KVAG, output file will be broken\n",
+               file_size);
+    }
+
+    return 0;
+}
+
+AVOutputFormat ff_kvag_muxer = {
+    .name           = "kvag",
+    .long_name      = NULL_IF_CONFIG_SMALL("Simon & Schuster Interactive VAG"),
+    .extensions     = "vag",
+    .audio_codec    = AV_CODEC_ID_ADPCM_IMA_SSI,
+    .video_codec    = AV_CODEC_ID_NONE,
+    .write_header   = kvag_write_header,
+    .write_packet   = kvag_write_packet,
+    .write_trailer  = kvag_write_trailer
+};
+#endif
diff --git a/libavformat/version.h b/libavformat/version.h
index 18c2f5fec2..493a0b337f 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  42
+#define LIBAVFORMAT_VERSION_MINOR  43
 #define LIBAVFORMAT_VERSION_MICRO 100
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
-- 
2.17.1