Chronomaster DFA decoder

Signed-off-by: Anton Khirnov <anton@khirnov.net>
2025-12-15 19:40:07 +01:00 · 2011-03-15 09:37:48 +01:00
parent c6f951442e
commit 42315dabce
11 changed files with 526 additions and 2 deletions
--- a/libavformat/dfa.c
+++ b/libavformat/dfa.c
@@ -0,0 +1,119 @@
+/*
+ * Chronomaster DFA Format Demuxer
+ * Copyright (c) 2011 Konstantin Shishkov
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/intreadwrite.h"
+#include "avformat.h"
+
+static int dfa_probe(AVProbeData *p)
+{
+    if (p->buf_size < 4 || AV_RL32(p->buf) != MKTAG('D', 'F', 'I', 'A'))
+        return 0;
+
+    return AVPROBE_SCORE_MAX;
+}
+
+static int dfa_read_header(AVFormatContext *s,
+                           AVFormatParameters *ap)
+{
+    AVIOContext *pb = s->pb;
+    AVStream *st;
+    int frames;
+    uint32_t mspf;
+
+    if (avio_rl32(pb) != MKTAG('D', 'F', 'I', 'A')) {
+        av_log(s, AV_LOG_ERROR, "Invalid magic for DFA\n");
+        return AVERROR_INVALIDDATA;
+    }
+    avio_skip(pb, 2); // unused
+    frames = avio_rl16(pb);
+
+    st = av_new_stream(s, 0);
+    if (!st)
+        return AVERROR(ENOMEM);
+
+    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
+    st->codec->codec_id   = CODEC_ID_DFA;
+    st->codec->width      = avio_rl16(pb);
+    st->codec->height     = avio_rl16(pb);
+    mspf = avio_rl32(pb);
+    if (!mspf) {
+        av_log(s, AV_LOG_WARNING, "Zero FPS reported, defaulting to 10\n");
+        mspf = 100;
+    }
+    av_set_pts_info(st, 24, mspf, 1000);
+    avio_skip(pb, 128 - 16); // padding
+    st->duration = frames;
+
+    return 0;
+}
+
+static int dfa_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    AVIOContext *pb = s->pb;
+    uint32_t frame_size;
+    int ret, first = 1;
+
+    if (pb->eof_reached)
+        return AVERROR_EOF;
+
+    if (av_get_packet(pb, pkt, 12) != 12)
+        return AVERROR(EIO);
+    while (!pb->eof_reached) {
+        if (!first) {
+            ret = av_append_packet(pb, pkt, 12);
+            if (ret < 0) {
+                av_free_packet(pkt);
+                return ret;
+            }
+        } else
+            first = 0;
+        frame_size = AV_RL32(pkt->data + pkt->size - 8);
+        if (frame_size > INT_MAX - 4) {
+            av_log(s, AV_LOG_ERROR, "Too large chunk size: %d\n", frame_size);
+            return AVERROR(EIO);
+        }
+        if (AV_RL32(pkt->data + pkt->size - 12) == MKTAG('E', 'O', 'F', 'R')) {
+            if (frame_size) {
+                av_log(s, AV_LOG_WARNING, "skipping %d bytes of end-of-frame marker chunk\n",
+                       frame_size);
+                avio_skip(pb, frame_size);
+            }
+            return 0;
+        }
+        ret = av_append_packet(pb, pkt, frame_size);
+        if (ret < 0) {
+            av_free_packet(pkt);
+            return ret;
+        }
+    }
+
+    return 0;
+}
+
+AVInputFormat ff_dfa_demuxer = {
+    "dfa",
+    NULL_IF_CONFIG_SMALL("Chronomaster DFA"),
+    0,
+    dfa_probe,
+    dfa_read_header,
+    dfa_read_packet,
+    .flags = AVFMT_GENERIC_INDEX,
+};