Microsoft Windows ICO demuxer

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 166 insertions, 0 deletions

diff --git a/libavformat/icodec.c b/libavformat/icodec.c
new file mode 100644
index 0000000000..e539b02464
--- /dev/null
+++ b/libavformat/icodec.c
@@ -0,0 +1,166 @@
+/*
+ * Microsoft Windows ICO demuxer
+ * Copyright (c) 2011 Peter Ross (pross@xvid.org)
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * Microsoft Windows ICO demuxer
+ */
+
+#include "libavutil/intreadwrite.h"
+#include "libavcodec/bytestream.h"
+#include "libavcodec/bmp.h"
+#include "avformat.h"
+#include "internal.h"
+
+typedef struct {
+    int offset;
+    int size;
+    int nb_pal;
+} IcoImage;
+
+typedef struct {
+    int current_image;
+    int nb_images;
+    IcoImage * images;
+} IcoDemuxContext;
+
+static int probe(AVProbeData *p)
+{
+    if (AV_RL16(p->buf) == 0 && AV_RL16(p->buf + 2) == 1 && AV_RL16(p->buf + 4))
+        return AVPROBE_SCORE_MAX / 3;
+    return 0;
+}
+
+static int read_header(AVFormatContext *s, AVFormatParameters *ap)
+{
+    IcoDemuxContext *ico = s->priv_data;
+    AVIOContext *pb = s->pb;
+    int i;
+
+    avio_skip(pb, 4);
+    ico->nb_images = avio_rl16(pb);
+
+    ico->images = av_malloc(ico->nb_images * sizeof(IcoImage));
+    if (!ico->images)
+        return AVERROR(ENOMEM);
+
+    for (i = 0; i < ico->nb_images; i++) {
+        AVStream *st;
+
+        if (avio_seek(pb, 6 + i * 16, SEEK_SET) < 0)
+            break;
+
+        st = avformat_new_stream(s, NULL);
+        if (!st)
+            return AVERROR(ENOMEM);
+
+        st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
+        st->codec->width      = avio_r8(pb);
+        st->codec->height     = avio_r8(pb);
+        ico->images[i].nb_pal = avio_r8(pb);
+
+        avio_skip(pb, 3);
+        st->codec->bits_per_coded_sample = avio_rl16(pb);
+        if (st->codec->bits_per_coded_sample <= 8 && !ico->images[i].nb_pal)
+            ico->images[i].nb_pal = 1 << st->codec->bits_per_coded_sample;
+
+        ico->images[i].size   = avio_rl32(pb);
+        ico->images[i].offset = avio_rl32(pb);
+
+        if (avio_seek(pb, ico->images[i].offset, SEEK_SET) < 0)
+            break;
+
+        switch(avio_rl32(pb)) {
+        case MKTAG(0x89, 'P', 'N', 'G'):
+            st->codec->codec_id = CODEC_ID_PNG;
+            st->codec->width    = 0;
+            st->codec->height   = 0;
+            break;
+        case 40:
+            st->codec->codec_id = CODEC_ID_BMP;
+            if (!st->codec->width || !st->codec->height) {
+                st->codec->width  = avio_rl32(pb);
+                st->codec->height = avio_rl32(pb) / 2;
+            }
+            break;
+        default:
+            av_log_ask_for_sample(s, "unsupported codec\n");
+            return AVERROR_INVALIDDATA;
+        }
+    }
+
+    return 0;
+}
+
+static int read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    IcoDemuxContext *ico = s->priv_data;
+    IcoImage *image;
+    AVIOContext *pb = s->pb;
+    int ret;
+
+    if (ico->current_image >= ico->nb_images)
+        return AVERROR(EIO);
+
+    image = &ico->images[ico->current_image];
+
+    if ((ret = avio_seek(pb, image->offset, SEEK_SET)) < 0)
+        return ret;
+
+    if (s->streams[ico->current_image]->codec->codec_id == CODEC_ID_PNG) {
+        if ((ret = av_get_packet(pb, pkt, image->size)) < 0)
+            return ret;
+    } else {
+        uint8_t *buf;
+        if ((ret = av_new_packet(pkt, 14 + image->size)) < 0)
+            return ret;
+        buf = pkt->data;
+
+        /* add BMP header */
+        bytestream_put_byte(&buf, 'B');
+        bytestream_put_byte(&buf, 'M');
+        bytestream_put_le32(&buf, pkt->size);
+        bytestream_put_le16(&buf, 0);
+        bytestream_put_le16(&buf, 0);
+        bytestream_put_le32(&buf, 14 + 40 + image->nb_pal * 4);
+
+        if ((ret = avio_read(pb, buf, image->size)) < 0)
+            return ret;
+
+        AV_WL32(buf + 8, AV_RL32(buf + 8) / 2);
+        AV_WL32(buf + 32, image->nb_pal);
+    }
+
+    pkt->stream_index = ico->current_image++;
+    pkt->flags |= AV_PKT_FLAG_KEY;
+
+    return 0;
+}
+
+AVInputFormat ff_ico_demuxer = {
+    .name           = "ico",
+    .long_name      = NULL_IF_CONFIG_SMALL("Microsoft Windows ICO"),
+    .priv_data_size = sizeof(IcoDemuxContext),
+    .read_probe     = probe,
+    .read_header    = read_header,
+    .read_packet    = read_packet,
+    .flags          = AVFMT_NOTIMESTAMPS,
+};