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  av_log(s, AV_LOG_ERROR, "Unsupported codec %s\n", c->codec_name);
65  return AVERROR(EINVAL);
66  }
67 
68  if (c->width > 256 ||
69  c->height > 256) {
70  av_log(s, AV_LOG_ERROR, "Unsupported dimensions %dx%d (dimensions cannot exceed 256x256)\n", c->width, c->height);
71  return AVERROR(EINVAL);
72  }
73 
74  return 0;
75 }
76 
77  static int ico_write_header(AVFormatContext *s)
78 {
79  IcoMuxContext *ico = s->priv_data;
80  AVIOContext *pb = s->pb;
81  int ret;
82  int i;
83 
84  if (!pb->seekable) {
85  av_log(s, AV_LOG_ERROR, "Output is not seekable\n");
86  return AVERROR(EINVAL);
87  }
88 
89  ico->current_image = 0;
90  ico->nb_images = s->nb_streams;
91 
92  avio_wl16(pb, 0); // reserved
93  avio_wl16(pb, 1); // 1 == icon
94  avio_skip(pb, 2); // skip the number of images
95 
96  for (i = 0; i < s->nb_streams; i++) {
97  if (ret = ico_check_attributes(s, s->streams[i]->codec))
98  return ret;
99 
100  // Fill in later when writing trailer...
101  avio_skip(pb, 16);
102  }
103 
104  ico->images = av_mallocz(ico->nb_images * sizeof(IcoMuxContext));
105  if (!ico->images)
106  return AVERROR(ENOMEM);
107 
108  avio_flush(pb);
109 
110  return 0;
111 }
112 
113  static int ico_write_packet(AVFormatContext *s, AVPacket *pkt)
114 {
115  IcoMuxContext *ico = s->priv_data;
116  IcoImage *image;
117  AVIOContext *pb = s->pb;
118  AVCodecContext *c = s->streams[pkt->stream_index]->codec;
119  int i;
120 
121  if (ico->current_image >= ico->nb_images) {
122  av_log(s, AV_LOG_ERROR, "ICO already contains %d images\n", ico->current_image);
123  return AVERROR(EIO);
124  }
125 
126  image = &ico->images[ico->current_image++];
127 
128  image->offset = avio_tell(pb);
129  image->width = (c->width == 256) ? 0 : c->width;
130  image->height = (c->height == 256) ? 0 : c->height;
131 
132  if (c->codec_id == AV_CODEC_ID_PNG) {
133  image->bits = c->bits_per_coded_sample;
134  image->size = pkt->size;
135 
136  avio_write(pb, pkt->data, pkt->size);
137  } else { // BMP
138  if (AV_RL32(pkt->data + 14) != 40) { // must be BITMAPINFOHEADER
139  av_log(s, AV_LOG_ERROR, "Invalid BMP\n");
140  return AVERROR(EINVAL);
141  }
142 
143  image->bits = AV_RL16(pkt->data + 28); // allows things like 1bit and 4bit images to be preserved
144  image->size = pkt->size - 14 + c->height * (c->width + 7) / 8;
145 
146  avio_write(pb, pkt->data + 14, 8); // Skip the BITMAPFILEHEADER header
147  avio_wl32(pb, AV_RL32(pkt->data + 22) * 2); // rewrite height as 2 * height
148  avio_write(pb, pkt->data + 26, pkt->size - 26);
149 
150  for (i = 0; i < c->height * (c->width + 7) / 8; ++i)
151  avio_w8(pb, 0x00); // Write bitmask (opaque)
152  }
153 
154  return 0;
155 }
156 
157  static int ico_write_trailer(AVFormatContext *s)
158 {
159  IcoMuxContext *ico = s->priv_data;
160  AVIOContext *pb = s->pb;
161  int i;
162 
163  avio_seek(pb, 4, SEEK_SET);
164 
165  avio_wl16(pb, ico->current_image);
166 
167  for (i = 0; i < ico->nb_images; i++) {
168  avio_w8(pb, ico->images[i].width);
169  avio_w8(pb, ico->images[i].height);
170 
171  if (s->streams[i]->codec->codec_id == AV_CODEC_ID_BMP &&
172  s->streams[i]->codec->pix_fmt == AV_PIX_FMT_PAL8) {
173  avio_w8(pb, (ico->images[i].bits >= 8) ? 0 : 1 << ico->images[i].bits);
174  } else {
175  avio_w8(pb, 0);
176  }
177 
178  avio_w8(pb, 0); // reserved
179  avio_wl16(pb, 1); // color planes
180  avio_wl16(pb, ico->images[i].bits);
181  avio_wl32(pb, ico->images[i].size);
182  avio_wl32(pb, ico->images[i].offset);
183  }
184 
185  av_freep(&ico->images);
186 
187  return 0;
188 }
189 
190  AVOutputFormat ff_ico_muxer = {
191  .name = "ico",
192  .long_name = NULL_IF_CONFIG_SMALL("Microsoft Windows ICO"),
193  .priv_data_size = sizeof(IcoMuxContext),
194  .mime_type = "image/vnd.microsoft.icon",
195  .extensions = "ico",
196  .audio_codec = AV_CODEC_ID_NONE,
197  .video_codec = AV_CODEC_ID_BMP,
198  .write_header = ico_write_header,
199  .write_packet = ico_write_packet,
200  .write_trailer = ico_write_trailer,
201  .flags = AVFMT_NOTIMESTAMPS,
202 };
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