avformat: add demuxer for argonaut games' ASF format

Adds support for the custom ASF container used by some Argonaut Games'
games, such as 'Croc! Legend of the Gobbos', and 'Croc 2'.

Can also handle the sample files in:
https://samples.ffmpeg.org/game-formats/brender/part2.zip

Signed-off-by: Zane van Iperen <zane@zanevaniperen.com>

1 files changed, 249 insertions, 0 deletions

diff --git a/libavformat/argo_asf.c b/libavformat/argo_asf.c
new file mode 100644
index 0000000000..3339425244
--- /dev/null
+++ b/libavformat/argo_asf.c
@@ -0,0 +1,249 @@
+/*
+ * Argonaut Games ASF demuxer
+ *
+ * Copyright (C) 2020 Zane van Iperen (zane@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"
+#include "libavutil/avassert.h"
+
+#define ASF_TAG                 MKTAG('A', 'S', 'F', '\0')
+#define ASF_FILE_HEADER_SIZE    24
+#define ASF_CHUNK_HEADER_SIZE   20
+
+typedef struct ArgoASFFileHeader {
+    uint32_t    magic;          /*< Magic Number, {'A', 'S', 'F', '\0'} */
+    uint16_t    version_major;  /*< File Major Version. */
+    uint16_t    version_minor;  /*< File Minor Version. */
+    uint32_t    num_chunks;     /*< No. chunks in the file. */
+    uint32_t    chunk_offset;   /*< Offset to the first chunk from the start of the file. */
+    int8_t      name[8];        /*< Name. */
+} ArgoASFFileHeader;
+
+typedef struct ArgoASFChunkHeader {
+    uint32_t    num_blocks;     /*< No. blocks in the chunk. */
+    uint32_t    num_samples;    /*< No. samples per channel in a block. */
+    uint32_t    unk1;           /*< Unknown */
+    uint16_t    sample_rate;    /*< Sample rate. */
+    uint16_t    unk2;           /*< Unknown. */
+    uint32_t    flags;          /*< Stream flags. */
+} ArgoASFChunkHeader;
+
+enum {
+    ASF_CF_BITS_PER_SAMPLE  = (1 << 0), /*< 16-bit if set, 8 otherwise.      */
+    ASF_CF_STEREO           = (1 << 1), /*< Stereo if set, mono otherwise.   */
+    ASF_CF_ALWAYS1_1        = (1 << 2), /*< Unknown, always seems to be set. */
+    ASF_CF_ALWAYS1_2        = (1 << 3), /*< Unknown, always seems to be set. */
+
+    ASF_CF_ALWAYS1          = ASF_CF_ALWAYS1_1 | ASF_CF_ALWAYS1_2,
+    ASF_CF_ALWAYS0          = ~(ASF_CF_BITS_PER_SAMPLE | ASF_CF_STEREO | ASF_CF_ALWAYS1)
+};
+
+typedef struct ArgoASFDemuxContext {
+    ArgoASFFileHeader   fhdr;
+    ArgoASFChunkHeader  ckhdr;
+    uint32_t            blocks_read;
+} ArgoASFDemuxContext;
+
+static void argo_asf_parse_file_header(ArgoASFFileHeader *hdr, const uint8_t *buf)
+{
+    hdr->magic          = AV_RL32(buf + 0);
+    hdr->version_major  = AV_RL16(buf + 4);
+    hdr->version_minor  = AV_RL16(buf + 6);
+    hdr->num_chunks     = AV_RL32(buf + 8);
+    hdr->chunk_offset   = AV_RL32(buf + 12);
+    for (int i = 0; i < FF_ARRAY_ELEMS(hdr->name); i++)
+        hdr->name[i]    = AV_RL8(buf + 16 + i);
+}
+
+static void argo_asf_parse_chunk_header(ArgoASFChunkHeader *hdr, const uint8_t *buf)
+{
+    hdr->num_blocks     = AV_RL32(buf + 0);
+    hdr->num_samples    = AV_RL32(buf + 4);
+    hdr->unk1           = AV_RL32(buf + 8);
+    hdr->sample_rate    = AV_RL16(buf + 12);
+    hdr->unk2           = AV_RL16(buf + 14);
+    hdr->flags          = AV_RL32(buf + 16);
+}
+
+/*
+ * Known versions:
+ * 1.1: The sample files in /game-formats/brender/part2.zip
+ * 1.2: Croc! Legend of the Gobbos
+ * 2.1: Croc 2
+ */
+static int argo_asf_is_known_version(const ArgoASFFileHeader *hdr)
+{
+    return (hdr->version_major == 1 && hdr->version_minor == 1) ||
+           (hdr->version_major == 1 && hdr->version_minor == 2) ||
+           (hdr->version_major == 2 && hdr->version_minor == 1);
+}
+
+static int argo_asf_probe(const AVProbeData *p)
+{
+    ArgoASFFileHeader hdr;
+
+    av_assert0(AVPROBE_PADDING_SIZE >= ASF_FILE_HEADER_SIZE);
+
+    argo_asf_parse_file_header(&hdr, p->buf);
+
+    if (hdr.magic != ASF_TAG)
+        return 0;
+
+    if (!argo_asf_is_known_version(&hdr))
+        return AVPROBE_SCORE_EXTENSION / 2;
+
+    return AVPROBE_SCORE_EXTENSION + 1;
+}
+
+static int argo_asf_read_header(AVFormatContext *s)
+{
+    int64_t ret;
+    AVIOContext *pb = s->pb;
+    AVStream *st;
+    ArgoASFDemuxContext *asf = s->priv_data;
+    uint8_t buf[FFMAX(ASF_FILE_HEADER_SIZE, ASF_CHUNK_HEADER_SIZE)];
+
+    if (!(st = avformat_new_stream(s, NULL)))
+        return AVERROR(ENOMEM);
+
+    if ((ret = avio_read(pb, buf, ASF_FILE_HEADER_SIZE)) < 0)
+        return ret;
+    else if (ret != ASF_FILE_HEADER_SIZE)
+        return AVERROR(EIO);
+
+    argo_asf_parse_file_header(&asf->fhdr, buf);
+
+    if (!argo_asf_is_known_version(&asf->fhdr)) {
+        avpriv_request_sample(s, "Version %hu.%hu",
+            asf->fhdr.version_major, asf->fhdr.version_minor
+        );
+        return AVERROR_PATCHWELCOME;
+    }
+
+    if (asf->fhdr.num_chunks == 0) {
+        return AVERROR_INVALIDDATA;
+    } else if (asf->fhdr.num_chunks > 1) {
+        avpriv_request_sample(s, ">1 chunk");
+        return AVERROR_PATCHWELCOME;
+    }
+
+    if (asf->fhdr.chunk_offset < ASF_FILE_HEADER_SIZE)
+        return AVERROR_INVALIDDATA;
+
+    if ((ret = avio_skip(pb, asf->fhdr.chunk_offset - ASF_FILE_HEADER_SIZE)) < 0)
+        return ret;
+
+    if ((ret = avio_read(pb, buf, ASF_CHUNK_HEADER_SIZE)) < 0)
+        return ret;
+    else if (ret != ASF_CHUNK_HEADER_SIZE)
+        return AVERROR(EIO);
+
+    argo_asf_parse_chunk_header(&asf->ckhdr, buf);
+
+    if ((asf->ckhdr.flags & ASF_CF_ALWAYS1) != ASF_CF_ALWAYS1 || (asf->ckhdr.flags & ASF_CF_ALWAYS0) != 0) {
+        avpriv_request_sample(s, "Nonstandard flags (0x%08X)", asf->ckhdr.flags);
+        return AVERROR_PATCHWELCOME;
+    }
+
+    st->codecpar->codec_type                = AVMEDIA_TYPE_AUDIO;
+    st->codecpar->codec_id                  = AV_CODEC_ID_ADPCM_ARGO;
+    st->codecpar->format                    = AV_SAMPLE_FMT_S16P;
+
+    if (asf->ckhdr.flags & ASF_CF_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               = asf->ckhdr.sample_rate;
+
+    st->codecpar->bits_per_coded_sample     = 4;
+
+    if (asf->ckhdr.flags & ASF_CF_BITS_PER_SAMPLE)
+        st->codecpar->bits_per_raw_sample   = 16;
+    else
+        st->codecpar->bits_per_raw_sample   = 8;
+
+    if (st->codecpar->bits_per_raw_sample != 16) {
+        /* The header allows for these, but I've never seen any files with them. */
+        avpriv_request_sample(s, "Non 16-bit samples");
+        return AVERROR_PATCHWELCOME;
+    }
+
+    /*
+     * (nchannel control bytes) + ((bytes_per_channel) * nchannel)
+     * For mono, this is 17. For stereo, this is 34.
+     */
+    st->codecpar->frame_size            = st->codecpar->channels +
+                                          (asf->ckhdr.num_samples / 2) *
+                                          st->codecpar->channels;
+
+    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->duration        = asf->ckhdr.num_blocks * asf->ckhdr.num_samples;
+    st->nb_frames       = asf->ckhdr.num_blocks;
+    return 0;
+}
+
+static int argo_asf_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    ArgoASFDemuxContext *asf = s->priv_data;
+
+    AVStream *st = s->streams[0];
+    AVIOContext *pb = s->pb;
+    int ret;
+
+    if (asf->blocks_read >= asf->ckhdr.num_blocks)
+        return AVERROR_EOF;
+
+    if ((ret = av_get_packet(pb, pkt, st->codecpar->frame_size)) < 0)
+        return ret;
+    else if (ret != st->codecpar->frame_size)
+        return AVERROR_INVALIDDATA;
+
+    pkt->stream_index   = st->index;
+    pkt->duration       = asf->ckhdr.num_samples;
+
+    ++asf->blocks_read;
+    return 0;
+}
+
+/*
+ * Not actually sure what ASF stands for.
+ * - Argonaut Sound File?
+ * - Audio Stream File?
+ */
+AVInputFormat ff_argo_asf_demuxer = {
+    .name           = "argo_asf",
+    .long_name      = NULL_IF_CONFIG_SMALL("Argonaut Games ASF"),
+    .priv_data_size = sizeof(ArgoASFDemuxContext),
+    .read_probe     = argo_asf_probe,
+    .read_header    = argo_asf_read_header,
+    .read_packet    = argo_asf_read_packet
+};