icoenc.c 6.04 KB
Newer Older
Michael Bradshaw's avatar
Michael Bradshaw committed
1 2
/*
 * Microsoft Windows ICO muxer
3
 * Copyright (c) 2012 Michael Bradshaw <mjbshaw gmail com>
Michael Bradshaw's avatar
Michael Bradshaw committed
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46
 *
 * 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 muxer
 */

#include "libavutil/intreadwrite.h"
#include "libavutil/pixdesc.h"
#include "avformat.h"

typedef struct {
    int offset;
    int size;
    unsigned char width;
    unsigned char height;
    short bits;
} IcoImage;

typedef struct {
    int current_image;
    int nb_images;
    IcoImage *images;
} IcoMuxContext;

static int ico_check_attributes(AVFormatContext *s, const AVCodecContext *c)
{
47
    if (c->codec_id == AV_CODEC_ID_BMP) {
48
        if (c->pix_fmt == AV_PIX_FMT_PAL8 && AV_PIX_FMT_RGB32 != AV_PIX_FMT_BGRA) {
Michael Bradshaw's avatar
Michael Bradshaw committed
49 50
            av_log(s, AV_LOG_ERROR, "Wrong endianness for bmp pixel format\n");
            return AVERROR(EINVAL);
51 52 53 54
        } else if (c->pix_fmt != AV_PIX_FMT_PAL8 &&
                   c->pix_fmt != AV_PIX_FMT_RGB555LE &&
                   c->pix_fmt != AV_PIX_FMT_BGR24 &&
                   c->pix_fmt != AV_PIX_FMT_BGRA) {
Michael Bradshaw's avatar
Michael Bradshaw committed
55 56 57
            av_log(s, AV_LOG_ERROR, "BMP must be 1bit, 4bit, 8bit, 16bit, 24bit, or 32bit\n");
            return AVERROR(EINVAL);
        }
58
    } else if (c->codec_id == AV_CODEC_ID_PNG) {
59
        if (c->pix_fmt != AV_PIX_FMT_RGBA) {
Michael Bradshaw's avatar
Michael Bradshaw committed
60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131
            av_log(s, AV_LOG_ERROR, "PNG in ico requires pixel format to be rgba\n");
            return AVERROR(EINVAL);
        }
    } else {
        av_log(s, AV_LOG_ERROR, "Unsupported codec %s\n", c->codec_name);
        return AVERROR(EINVAL);
    }

    if (c->width > 256 ||
        c->height > 256) {
        av_log(s, AV_LOG_ERROR, "Unsupported dimensions %dx%d (dimensions cannot exceed 256x256)\n", c->width, c->height);
        return AVERROR(EINVAL);
    }

    return 0;
}

static int ico_write_header(AVFormatContext *s)
{
    IcoMuxContext *ico = s->priv_data;
    AVIOContext *pb = s->pb;
    int ret;
    int i;

    if (!pb->seekable) {
        av_log(s, AV_LOG_ERROR, "Output is not seekable\n");
        return AVERROR(EINVAL);
    }

    ico->current_image = 0;
    ico->nb_images = s->nb_streams;

    avio_wl16(pb, 0); // reserved
    avio_wl16(pb, 1); // 1 == icon
    avio_skip(pb, 2); // skip the number of images

    for (i = 0; i < s->nb_streams; i++) {
        if (ret = ico_check_attributes(s, s->streams[i]->codec))
            return ret;

        // Fill in later when writing trailer...
        avio_skip(pb, 16);
    }

    ico->images = av_mallocz(ico->nb_images * sizeof(IcoMuxContext));
    if (!ico->images)
        return AVERROR(ENOMEM);

    avio_flush(pb);

    return 0;
}

static int ico_write_packet(AVFormatContext *s, AVPacket *pkt)
{
    IcoMuxContext *ico = s->priv_data;
    IcoImage *image;
    AVIOContext *pb = s->pb;
    AVCodecContext *c = s->streams[pkt->stream_index]->codec;
    int i;

    if (ico->current_image >= ico->nb_images) {
        av_log(s, AV_LOG_ERROR, "ICO already contains %d images\n", ico->current_image);
        return AVERROR(EIO);
    }

    image = &ico->images[ico->current_image++];

    image->offset = avio_tell(pb);
    image->width = (c->width == 256) ? 0 : c->width;
    image->height = (c->height == 256) ? 0 : c->height;

132
    if (c->codec_id == AV_CODEC_ID_PNG) {
Michael Bradshaw's avatar
Michael Bradshaw committed
133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170
        image->bits = c->bits_per_coded_sample;
        image->size = pkt->size;

        avio_write(pb, pkt->data, pkt->size);
    } else { // BMP
        if (AV_RL32(pkt->data + 14) != 40) { // must be BITMAPINFOHEADER
            av_log(s, AV_LOG_ERROR, "Invalid BMP\n");
            return AVERROR(EINVAL);
        }

        image->bits = AV_RL16(pkt->data + 28); // allows things like 1bit and 4bit images to be preserved
        image->size = pkt->size - 14 + c->height * (c->width + 7) / 8;

        avio_write(pb, pkt->data + 14, 8); // Skip the BITMAPFILEHEADER header
        avio_wl32(pb, AV_RL32(pkt->data + 22) * 2); // rewrite height as 2 * height
        avio_write(pb, pkt->data + 26, pkt->size - 26);

        for (i = 0; i < c->height * (c->width + 7) / 8; ++i)
            avio_w8(pb, 0x00); // Write bitmask (opaque)
    }

    return 0;
}

static int ico_write_trailer(AVFormatContext *s)
{
    IcoMuxContext *ico = s->priv_data;
    AVIOContext *pb = s->pb;
    int i;

    avio_seek(pb, 4, SEEK_SET);

    avio_wl16(pb, ico->current_image);

    for (i = 0; i < ico->nb_images; i++) {
        avio_w8(pb, ico->images[i].width);
        avio_w8(pb, ico->images[i].height);

171
        if (s->streams[i]->codec->codec_id == AV_CODEC_ID_BMP &&
172
            s->streams[i]->codec->pix_fmt == AV_PIX_FMT_PAL8) {
Michael Bradshaw's avatar
Michael Bradshaw committed
173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195
            avio_w8(pb, (ico->images[i].bits >= 8) ? 0 : 1 << ico->images[i].bits);
        } else {
            avio_w8(pb, 0);
        }

        avio_w8(pb, 0); // reserved
        avio_wl16(pb, 1); // color planes
        avio_wl16(pb, ico->images[i].bits);
        avio_wl32(pb, ico->images[i].size);
        avio_wl32(pb, ico->images[i].offset);
    }

    av_freep(&ico->images);

    return 0;
}

AVOutputFormat ff_ico_muxer = {
    .name           = "ico",
    .long_name      = NULL_IF_CONFIG_SMALL("Microsoft Windows ICO"),
    .priv_data_size = sizeof(IcoMuxContext),
    .mime_type      = "image/vnd.microsoft.icon",
    .extensions     = "ico",
196 197
    .audio_codec    = AV_CODEC_ID_NONE,
    .video_codec    = AV_CODEC_ID_BMP,
Michael Bradshaw's avatar
Michael Bradshaw committed
198 199 200 201 202
    .write_header   = ico_write_header,
    .write_packet   = ico_write_packet,
    .write_trailer  = ico_write_trailer,
    .flags          = AVFMT_NOTIMESTAMPS,
};