FFmpeg: libavformat/icoenc.c Source File

FFmpeg
icoenc.c
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1 /*
2  * Microsoft Windows ICO muxer
3  * Copyright (c) 2012 Michael Bradshaw <mjbshaw gmail com>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * Microsoft Windows ICO muxer
25  */
26 
27 #include "libavutil/intreadwrite.h"
28 #include "libavutil/pixdesc.h"
29 #include "avformat.h"
30 
31 typedef struct {
32  int offset;
33  int size;
34   unsigned char width;
35   unsigned char height;
36   short bits;
37 } IcoImage;
38 
39  typedef struct {
40   int current_image;
41   int nb_images;
42   IcoImage *images;
43 } IcoMuxContext;
44 
45  static int ico_check_attributes(AVFormatContext *s, const AVCodecContext *c)
46 {
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) {
49  av_log(s, AV_LOG_ERROR, "Wrong endianness for bmp pixel format\n");
50  return AVERROR(EINVAL);
51  } else if (c->pix_fmt != AV_PIX_FMT_PAL8 &&
52  c->pix_fmt != AV_PIX_FMT_RGB555LE &&
53  c->pix_fmt != AV_PIX_FMT_BGR24 &&
54  c->pix_fmt != AV_PIX_FMT_BGRA) {
55  av_log(s, AV_LOG_ERROR, "BMP must be 1bit, 4bit, 8bit, 16bit, 24bit, or 32bit\n");
56  return AVERROR(EINVAL);
57  }
58  } else if (c->codec_id == AV_CODEC_ID_PNG) {
59  if (c->pix_fmt != AV_PIX_FMT_RGBA) {
60  av_log(s, AV_LOG_ERROR, "PNG in ico requires pixel format to be rgba\n");
61  return AVERROR(EINVAL);
62  }
63  } else {
64  const AVCodecDescriptor *codesc = avcodec_descriptor_get(c->codec_id);
65  av_log(s, AV_LOG_ERROR, "Unsupported codec %s\n", codesc ? codesc->name : "");
66  return AVERROR(EINVAL);
67  }
68 
69  if (c->width > 256 ||
70  c->height > 256) {
71  av_log(s, AV_LOG_ERROR, "Unsupported dimensions %dx%d (dimensions cannot exceed 256x256)\n", c->width, c->height);
72  return AVERROR(EINVAL);
73  }
74 
75  return 0;
76 }
77 
78  static int ico_write_header(AVFormatContext *s)
79 {
80  IcoMuxContext *ico = s->priv_data;
81  AVIOContext *pb = s->pb;
82  int ret;
83  int i;
84 
85  if (!pb->seekable) {
86  av_log(s, AV_LOG_ERROR, "Output is not seekable\n");
87  return AVERROR(EINVAL);
88  }
89 
90  ico->current_image = 0;
91  ico->nb_images = s->nb_streams;
92 
93  avio_wl16(pb, 0); // reserved
94  avio_wl16(pb, 1); // 1 == icon
95  avio_skip(pb, 2); // skip the number of images
96 
97  for (i = 0; i < s->nb_streams; i++) {
98  if (ret = ico_check_attributes(s, s->streams[i]->codec))
99  return ret;
100 
101  // Fill in later when writing trailer...
102  avio_skip(pb, 16);
103  }
104 
105  ico->images = av_mallocz_array(ico->nb_images, sizeof(IcoMuxContext));
106  if (!ico->images)
107  return AVERROR(ENOMEM);
108 
109  avio_flush(pb);
110 
111  return 0;
112 }
113 
114  static int ico_write_packet(AVFormatContext *s, AVPacket *pkt)
115 {
116  IcoMuxContext *ico = s->priv_data;
117  IcoImage *image;
118  AVIOContext *pb = s->pb;
119  AVCodecContext *c = s->streams[pkt->stream_index]->codec;
120  int i;
121 
122  if (ico->current_image >= ico->nb_images) {
123  av_log(s, AV_LOG_ERROR, "ICO already contains %d images\n", ico->current_image);
124  return AVERROR(EIO);
125  }
126 
127  image = &ico->images[ico->current_image++];
128 
129  image->offset = avio_tell(pb);
130  image->width = (c->width == 256) ? 0 : c->width;
131  image->height = (c->height == 256) ? 0 : c->height;
132 
133  if (c->codec_id == AV_CODEC_ID_PNG) {
134  image->bits = c->bits_per_coded_sample;
135  image->size = pkt->size;
136 
137  avio_write(pb, pkt->data, pkt->size);
138  } else { // BMP
139  if (AV_RL32(pkt->data + 14) != 40) { // must be BITMAPINFOHEADER
140  av_log(s, AV_LOG_ERROR, "Invalid BMP\n");
141  return AVERROR(EINVAL);
142  }
143 
144  image->bits = AV_RL16(pkt->data + 28); // allows things like 1bit and 4bit images to be preserved
145  image->size = pkt->size - 14 + c->height * (c->width + 7) / 8;
146 
147  avio_write(pb, pkt->data + 14, 8); // Skip the BITMAPFILEHEADER header
148  avio_wl32(pb, AV_RL32(pkt->data + 22) * 2); // rewrite height as 2 * height
149  avio_write(pb, pkt->data + 26, pkt->size - 26);
150 
151  for (i = 0; i < c->height * (c->width + 7) / 8; ++i)
152  avio_w8(pb, 0x00); // Write bitmask (opaque)
153  }
154 
155  return 0;
156 }
157 
158  static int ico_write_trailer(AVFormatContext *s)
159 {
160  IcoMuxContext *ico = s->priv_data;
161  AVIOContext *pb = s->pb;
162  int i;
163 
164  avio_seek(pb, 4, SEEK_SET);
165 
166  avio_wl16(pb, ico->current_image);
167 
168  for (i = 0; i < ico->nb_images; i++) {
169  avio_w8(pb, ico->images[i].width);
170  avio_w8(pb, ico->images[i].height);
171 
172  if (s->streams[i]->codec->codec_id == AV_CODEC_ID_BMP &&
173  s->streams[i]->codec->pix_fmt == AV_PIX_FMT_PAL8) {
174  avio_w8(pb, (ico->images[i].bits >= 8) ? 0 : 1 << ico->images[i].bits);
175  } else {
176  avio_w8(pb, 0);
177  }
178 
179  avio_w8(pb, 0); // reserved
180  avio_wl16(pb, 1); // color planes
181  avio_wl16(pb, ico->images[i].bits);
182  avio_wl32(pb, ico->images[i].size);
183  avio_wl32(pb, ico->images[i].offset);
184  }
185 
186  av_freep(&ico->images);
187 
188  return 0;
189 }
190 
191  AVOutputFormat ff_ico_muxer = {
192  .name = "ico",
193  .long_name = NULL_IF_CONFIG_SMALL("Microsoft Windows ICO"),
194  .priv_data_size = sizeof(IcoMuxContext),
195  .mime_type = "image/vnd.microsoft.icon",
196  .extensions = "ico",
197  .audio_codec = AV_CODEC_ID_NONE,
198  .video_codec = AV_CODEC_ID_BMP,
199  .write_header = ico_write_header,
200  .write_packet = ico_write_packet,
201  .write_trailer = ico_write_trailer,
202  .flags = AVFMT_NOTIMESTAMPS,
203 };
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