avformat: add RKA demuxer

Changelog

@@ -41,7 +41,7 @@ version <next>:
 - WavArc decoder and demuxer
 - CrystalHD decoders deprecated
 - SDNS demuxer
-- RKA decoder
+- RKA decoder and demuxer
 
 
 version 5.1:

doc/general_contents.texi

@@ -579,6 +579,7 @@ library:
 @item Ogg                       @tab X @tab X
 @item Playstation Portable PMP  @tab   @tab X
 @item Portable Voice Format     @tab   @tab X
+@item RK Audio (RKA)            @tab   @tab X
 @item TechnoTrend PVA           @tab   @tab X
     @tab Used by TechnoTrend DVB PCI boards.
 @item QCP                       @tab   @tab X

libavformat/Makefile

@@ -482,6 +482,7 @@ OBJS-$(CONFIG_RAWVIDEO_DEMUXER)          += rawvideodec.o
 OBJS-$(CONFIG_RAWVIDEO_MUXER)            += rawenc.o
 OBJS-$(CONFIG_REALTEXT_DEMUXER)          += realtextdec.o subtitles.o
 OBJS-$(CONFIG_REDSPARK_DEMUXER)          += redspark.o
+OBJS-$(CONFIG_RKA_DEMUXER)               += rka.o apetag.o img2.o
 OBJS-$(CONFIG_RL2_DEMUXER)               += rl2.o
 OBJS-$(CONFIG_RM_DEMUXER)                += rmdec.o rm.o rmsipr.o
 OBJS-$(CONFIG_RM_MUXER)                  += rmenc.o rm.o

libavformat/allformats.c

@@ -381,6 +381,7 @@ extern const AVInputFormat  ff_rawvideo_demuxer;
 extern const FFOutputFormat ff_rawvideo_muxer;
 extern const AVInputFormat  ff_realtext_demuxer;
 extern const AVInputFormat  ff_redspark_demuxer;
+extern const AVInputFormat  ff_rka_demuxer;
 extern const AVInputFormat  ff_rl2_demuxer;
 extern const AVInputFormat  ff_rm_demuxer;
 extern const FFOutputFormat ff_rm_muxer;

libavformat/rka.c

@@ -0,0 +1,173 @@
+/*
+ * RKA demuxer
+ * Copyright (c) 2023 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/dict.h"
+#include "libavutil/intreadwrite.h"
+
+#include "apetag.h"
+#include "avformat.h"
+#include "avio_internal.h"
+#include "demux.h"
+#include "internal.h"
+
+typedef struct RKAContext {
+    int total_frames, currentframe;
+    int frame_size;
+    int last_frame_size;
+} RKAContext;
+
+static int rka_probe(const AVProbeData *p)
+{
+    if (AV_RL32(&p->buf[0]) == MKTAG('R', 'K', 'A', '7') &&
+        AV_RL32(&p->buf[4]) > 0 &&
+        AV_RL32(&p->buf[8]) > 0 &&
+        p->buf[12] > 0 &&
+        p->buf[12] <= 2 &&
+        (p->buf[13] == 8 || p->buf[13] == 16) &&
+        p->buf[15] & 2 != 0)
+        return AVPROBE_SCORE_EXTENSION + 30;
+    return 0;
+}
+
+static int rka_read_header(AVFormatContext *s)
+{
+    int64_t nb_samples, size_offset;
+    RKAContext *c = s->priv_data;
+    int channels, bps, samplerate;
+    AVCodecParameters *par;
+    int64_t framepos;
+    AVStream *st;
+    int ret;
+
+    st = avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+
+    par = st->codecpar;
+    ret = ff_get_extradata(s, par, s->pb, 16);
+    if (ret < 0)
+        return ret;
+
+    nb_samples = AV_RL32(par->extradata + 4);
+    samplerate = AV_RL32(par->extradata + 8);
+    channels = par->extradata[12];
+    if (channels == 0)
+        return AVERROR_INVALIDDATA;
+    bps = par->extradata[13];
+    if (bps == 0)
+        return AVERROR_INVALIDDATA;
+    size_offset = avio_rl32(s->pb);
+    framepos = avio_tell(s->pb);
+    c->frame_size = 131072;
+
+    avpriv_set_pts_info(st, 64, 1, samplerate);
+    st->start_time = 0;
+
+    avio_seek(s->pb, size_offset, SEEK_SET);
+    c->total_frames = (nb_samples + c->frame_size - 1) / c->frame_size;
+    c->last_frame_size = nb_samples % c->frame_size;
+
+    for (int i = 0; i < c->total_frames; i++) {
+        int r, end = 0;
+        int64_t size;
+
+        if (avio_feof(s->pb))
+            break;
+
+        size = avio_rl24(s->pb);
+        if (size == 0) {
+            end = 1;
+            size = size_offset - framepos;
+            if (size <= 0)
+                break;
+        }
+
+        if ((r = av_add_index_entry(st, framepos, (i * 131072LL) / (channels * (bps >> 3)),
+                                    size, 0, AVINDEX_KEYFRAME)) < 0)
+            return r;
+        framepos += size;
+
+        if (end)
+            break;
+    }
+
+    par->codec_type = AVMEDIA_TYPE_AUDIO;
+    par->codec_id = AV_CODEC_ID_RKA;
+    par->ch_layout.nb_channels = channels;
+    par->sample_rate = samplerate;
+    par->bits_per_raw_sample = bps;
+    st->duration = nb_samples / (channels * (bps >> 3));
+
+    if (s->pb->seekable & AVIO_SEEKABLE_NORMAL)
+        ff_ape_parse_tag(s);
+
+    avio_seek(s->pb, 20, SEEK_SET);
+
+    return 0;
+}
+
+static int rka_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    RKAContext *c = s->priv_data;
+    AVStream *st = s->streams[0];
+    FFStream *const sti = ffstream(st);
+    int size, ret;
+
+    if (avio_feof(s->pb))
+        return AVERROR_EOF;
+
+    if (c->currentframe >= sti->nb_index_entries)
+        return AVERROR_EOF;
+
+    size = sti->index_entries[c->currentframe].size;
+
+    ret = av_get_packet(s->pb, pkt, size);
+    pkt->dts = sti->index_entries[c->currentframe++].timestamp;
+    pkt->duration = c->currentframe == c->total_frames ? c->last_frame_size :
+                                                         131072;
+    return ret;
+}
+
+static int rka_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
+{
+    RKAContext *c = s->priv_data;
+    AVStream *st = s->streams[stream_index];
+    int index = av_index_search_timestamp(st, timestamp, flags);
+    if (index < 0)
+        return -1;
+    if (avio_seek(s->pb, ffstream(st)->index_entries[index].pos, SEEK_SET) < 0)
+        return -1;
+
+    c->currentframe = index;
+
+    return 0;
+}
+
+const AVInputFormat ff_rka_demuxer = {
+    .name           = "rka",
+    .long_name      = NULL_IF_CONFIG_SMALL("RKA (RK Audio)"),
+    .priv_data_size = sizeof(RKAContext),
+    .read_probe     = rka_probe,
+    .read_header    = rka_read_header,
+    .read_packet    = rka_read_packet,
+    .read_seek      = rka_read_seek,
+    .extensions     = "rka",
+};

libavformat/version.h

@@ -31,7 +31,7 @@
 
 #include "version_major.h"
 
-#define LIBAVFORMAT_VERSION_MINOR   1
+#define LIBAVFORMAT_VERSION_MINOR   2
 #define LIBAVFORMAT_VERSION_MICRO 100
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \