avformat: add PDV demuxer

1 files changed, 173 insertions, 0 deletions

diff --git a/libavformat/pdvdec.c b/libavformat/pdvdec.c
new file mode 100644
index 0000000000..9d3f386e40
--- /dev/null
+++ b/libavformat/pdvdec.c
@@ -0,0 +1,173 @@
+/*
+ * PDV 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 "avformat.h"
+#include "internal.h"
+
+#define PDV_MAGIC "Playdate VID\x00\x00\x00\x00"
+
+typedef struct PDVDemuxContext {
+    int current_frame;
+    uint8_t *frame_flags;
+    uint32_t *frame_offsets;
+} PDVDemuxContext;
+
+static int pdv_probe(const AVProbeData *pd)
+{
+    if (strncmp(pd->buf, PDV_MAGIC, sizeof(PDV_MAGIC) - 1) == 0)
+        return AVPROBE_SCORE_MAX;
+    return 0;
+}
+
+static int pdv_read_header(AVFormatContext *s)
+{
+    PDVDemuxContext *p = s->priv_data;
+    AVIOContext *pb = s->pb;
+    AVCodecParameters *par;
+    AVStream *st;
+    uint64_t start;
+    uint32_t fps;
+
+    avio_skip(pb, 16);
+
+    st = avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+
+    par              = st->codecpar;
+    par->codec_type  = AVMEDIA_TYPE_VIDEO;
+    par->codec_id    = AV_CODEC_ID_PDV;
+    st->start_time   = 0;
+    st->duration     =
+    st->nb_frames    = avio_rl16(pb);
+    avio_skip(pb, 2);
+    fps = avio_rl32(pb);
+    st->avg_frame_rate = av_d2q(av_int2float(fps), INT_MAX);
+    par->width       = avio_rl16(pb);
+    par->height      = avio_rl16(pb);
+
+    avpriv_set_pts_info(st, 64, st->avg_frame_rate.den, st->avg_frame_rate.num);
+
+    p->current_frame = 0;
+    p->frame_flags = av_calloc(st->nb_frames + 1, sizeof(*p->frame_flags));
+    p->frame_offsets = av_calloc(st->nb_frames + 1, sizeof(*p->frame_offsets));
+
+    if (!p->frame_flags || !p->frame_offsets)
+        return AVERROR(ENOMEM);
+
+    for (int n = 0; n <= st->nb_frames; n++) {
+        const uint32_t entry = avio_rl32(pb);
+
+        p->frame_flags[n] = entry & 3;
+        p->frame_offsets[n] = entry >> 2;
+    }
+
+    start = avio_tell(pb);
+
+    for (int n = 0; n < st->nb_frames; n++) {
+        const uint64_t pos = start + p->frame_offsets[n];
+        const int32_t size = p->frame_offsets[n+1] - p->frame_offsets[n];
+        const int flags = p->frame_flags[n] & 1 ? AVINDEX_KEYFRAME : 0;
+
+        if (p->frame_flags[n] == 0 || size <= 0 ||
+            ((pb->seekable & AVIO_SEEKABLE_NORMAL) && pos + size > avio_size(pb)))
+            break;
+        av_add_index_entry(st, pos, n, size, 0, flags);
+    }
+
+    return 0;
+}
+
+static int pdv_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    PDVDemuxContext *p = s->priv_data;
+    AVStream *st = s->streams[0];
+    FFStream *const sti = ffstream(st);
+    AVIOContext *pb = s->pb;
+    int32_t size, flags, ret;
+    int64_t pos;
+
+    if (p->current_frame >= st->nb_frames)
+        return AVERROR_EOF;
+
+    if (p->current_frame >= sti->nb_index_entries)
+        return AVERROR(EIO);
+
+    pos   = sti->index_entries[p->current_frame].pos;
+    flags = sti->index_entries[p->current_frame].flags;
+    size  = sti->index_entries[p->current_frame].size;
+
+    avio_seek(pb, pos, SEEK_SET);
+    if (avio_feof(pb) || ((pb->seekable & AVIO_SEEKABLE_NORMAL) && pos + size > avio_size(pb)) || size == 0)
+        return AVERROR_EOF;
+
+    ret = av_get_packet(pb, pkt, size);
+    if (ret < 0)
+        return ret;
+
+    if (flags & AVINDEX_KEYFRAME)
+        pkt->flags |= AV_PKT_FLAG_KEY;
+    pkt->stream_index = 0;
+    pkt->pts = p->current_frame++;
+    pkt->duration = 1;
+
+    return 0;
+}
+
+static int pdv_read_close(AVFormatContext *s)
+{
+    PDVDemuxContext *p = s->priv_data;
+
+    av_freep(&p->frame_flags);
+    av_freep(&p->frame_offsets);
+
+    return 0;
+}
+
+static int pdv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
+{
+    PDVDemuxContext *p = 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;
+
+    p->current_frame = index;
+
+    return 0;
+}
+
+const AVInputFormat ff_pdv_demuxer = {
+    .name           = "pdv",
+    .long_name      = NULL_IF_CONFIG_SMALL("PlayDate Video"),
+    .priv_data_size = sizeof(PDVDemuxContext),
+    .flags_internal = FF_FMT_INIT_CLEANUP,
+    .read_probe     = pdv_probe,
+    .read_header    = pdv_read_header,
+    .read_packet    = pdv_read_packet,
+    .read_close     = pdv_read_close,
+    .read_seek      = pdv_read_seek,
+    .extensions     = "pdv",
+};