aboutsummaryrefslogtreecommitdiffstats
path: root/libavdevice/fbdev_enc.c
blob: b4e5f849759ff34452376740a2f8522cb5bcf3a4 (plain) (blame)
1
2
3
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
47
48
49
50
51
52
53
54
55
56
57
58
59
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
132
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
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
/*
 * Copyright (c) 2013 Lukasz Marek
 *
 * 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
 */

#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <linux/fb.h>
#include "libavutil/pixdesc.h"
#include "libavutil/log.h"
#include "libavutil/mem.h"
#include "libavutil/opt.h"
#include "libavformat/avformat.h"
#include "fbdev_common.h"
#include "avdevice.h"

typedef struct {
    AVClass *class;                   ///< class for private options
    int xoffset;                      ///< x coordinate of top left corner
    int yoffset;                      ///< y coordinate of top left corner
    struct fb_var_screeninfo varinfo; ///< framebuffer variable info
    struct fb_fix_screeninfo fixinfo; ///< framebuffer fixed info
    int fd;                           ///< framebuffer device file descriptor
    uint8_t *data;                    ///< framebuffer data
} FBDevContext;

static av_cold int fbdev_write_header(AVFormatContext *h)
{
    FBDevContext *fbdev = h->priv_data;
    enum AVPixelFormat pix_fmt;
    int ret, flags = O_RDWR;
    const char* device;

    if (h->nb_streams != 1 || h->streams[0]->codecpar->codec_type != AVMEDIA_TYPE_VIDEO) {
        av_log(fbdev, AV_LOG_ERROR, "Only a single video stream is supported.\n");
        return AVERROR(EINVAL);
    }

    if (h->filename[0])
        device = h->filename;
    else
        device = ff_fbdev_default_device();

    if ((fbdev->fd = avpriv_open(device, flags)) == -1) {
        ret = AVERROR(errno);
        av_log(h, AV_LOG_ERROR,
               "Could not open framebuffer device '%s': %s\n",
               device, av_err2str(ret));
        return ret;
    }

    if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0) {
        ret = AVERROR(errno);
        av_log(h, AV_LOG_ERROR, "FBIOGET_VSCREENINFO: %s\n", av_err2str(ret));
        goto fail;
    }

    if (ioctl(fbdev->fd, FBIOGET_FSCREENINFO, &fbdev->fixinfo) < 0) {
        ret = AVERROR(errno);
        av_log(h, AV_LOG_ERROR, "FBIOGET_FSCREENINFO: %s\n", av_err2str(ret));
        goto fail;
    }

    pix_fmt = ff_get_pixfmt_from_fb_varinfo(&fbdev->varinfo);
    if (pix_fmt == AV_PIX_FMT_NONE) {
        ret = AVERROR(EINVAL);
        av_log(h, AV_LOG_ERROR, "Framebuffer pixel format not supported.\n");
        goto fail;
    }

    fbdev->data = mmap(NULL, fbdev->fixinfo.smem_len, PROT_WRITE, MAP_SHARED, fbdev->fd, 0);
    if (fbdev->data == MAP_FAILED) {
        ret = AVERROR(errno);
        av_log(h, AV_LOG_ERROR, "Error in mmap(): %s\n", av_err2str(ret));
        goto fail;
    }

    return 0;
  fail:
    close(fbdev->fd);
    return ret;
}

static int fbdev_write_packet(AVFormatContext *h, AVPacket *pkt)
{
    FBDevContext *fbdev = h->priv_data;
    uint8_t *pin, *pout;
    enum AVPixelFormat fb_pix_fmt;
    int disp_height;
    int bytes_to_copy;
    AVCodecParameters *par = h->streams[0]->codecpar;
    enum AVPixelFormat video_pix_fmt = par->format;
    int video_width = par->width;
    int video_height = par->height;
    int bytes_per_pixel = ((par->bits_per_coded_sample + 7) >> 3);
    int src_line_size = video_width * bytes_per_pixel;
    int i;

    if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0)
        av_log(h, AV_LOG_WARNING,
               "Error refreshing variable info: %s\n", av_err2str(AVERROR(errno)));

    fb_pix_fmt = ff_get_pixfmt_from_fb_varinfo(&fbdev->varinfo);

    if (fb_pix_fmt != video_pix_fmt) {
        av_log(h, AV_LOG_ERROR, "Pixel format %s is not supported, use %s\n",
               av_get_pix_fmt_name(video_pix_fmt), av_get_pix_fmt_name(fb_pix_fmt));
        return AVERROR(EINVAL);
    }

    disp_height = FFMIN(fbdev->varinfo.yres, video_height);
    bytes_to_copy = FFMIN(fbdev->varinfo.xres, video_width) * bytes_per_pixel;

    pin  = pkt->data;
    pout = fbdev->data +
           bytes_per_pixel * fbdev->varinfo.xoffset +
           fbdev->varinfo.yoffset * fbdev->fixinfo.line_length;

    if (fbdev->xoffset) {
        if (fbdev->xoffset < 0) {
            if (-fbdev->xoffset >= video_width) //nothing to display
                return 0;
            bytes_to_copy += fbdev->xoffset * bytes_per_pixel;
            pin -= fbdev->xoffset * bytes_per_pixel;
        } else {
            int diff = (video_width + fbdev->xoffset) - fbdev->varinfo.xres;
            if (diff > 0) {
                if (diff >= video_width) //nothing to display
                    return 0;
                bytes_to_copy -= diff * bytes_per_pixel;
            }
            pout += bytes_per_pixel * fbdev->xoffset;
        }
    }

    if (fbdev->yoffset) {
        if (fbdev->yoffset < 0) {
            if (-fbdev->yoffset >= video_height) //nothing to display
                return 0;
            disp_height += fbdev->yoffset;
            pin -= fbdev->yoffset * src_line_size;
        } else {
            int diff = (video_height + fbdev->yoffset) - fbdev->varinfo.yres;
            if (diff > 0) {
                if (diff >= video_height) //nothing to display
                    return 0;
                disp_height -= diff;
            }
            pout += fbdev->yoffset * fbdev->fixinfo.line_length;
        }
    }

    for (i = 0; i < disp_height; i++) {
        memcpy(pout, pin, bytes_to_copy);
        pout += fbdev->fixinfo.line_length;
        pin  += src_line_size;
    }

    return 0;
}

static av_cold int fbdev_write_trailer(AVFormatContext *h)
{
    FBDevContext *fbdev = h->priv_data;
    munmap(fbdev->data, fbdev->fixinfo.smem_len);
    close(fbdev->fd);
    return 0;
}

static int fbdev_get_device_list(AVFormatContext *s, AVDeviceInfoList *device_list)
{
    return ff_fbdev_get_device_list(device_list);
}

#define OFFSET(x) offsetof(FBDevContext, x)
#define ENC AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
    { "xoffset", "set x coordinate of top left corner", OFFSET(xoffset), AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, ENC },
    { "yoffset", "set y coordinate of top left corner", OFFSET(yoffset), AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, ENC },
    { NULL }
};

static const AVClass fbdev_class = {
    .class_name = "fbdev outdev",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
    .category   = AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT,
};

AVOutputFormat ff_fbdev_muxer = {
    .name           = "fbdev",
    .long_name      = NULL_IF_CONFIG_SMALL("Linux framebuffer"),
    .priv_data_size = sizeof(FBDevContext),
    .audio_codec    = AV_CODEC_ID_NONE,
    .video_codec    = AV_CODEC_ID_RAWVIDEO,
    .write_header   = fbdev_write_header,
    .write_packet   = fbdev_write_packet,
    .write_trailer  = fbdev_write_trailer,
    .get_device_list = fbdev_get_device_list,
    .flags          = AVFMT_NOFILE | AVFMT_VARIABLE_FPS | AVFMT_NOTIMESTAMPS,
    .priv_class     = &fbdev_class,
};