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ffmpeg/libavdevice/fbdev.c

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/*
* Copyright (c) 2011 Stefano Sabatini
* Copyright (c) 2009 Giliard B. de Freitas <giliarde@gmail.com>
* Copyright (C) 2002 Gunnar Monell <gmo@linux.nu>
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Linux framebuffer input device,
* inspired by code from fbgrab.c by Gunnar Monell.
* @see http://linux-fbdev.sourceforge.net/
*/
/* #define DEBUG */
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <time.h>
#include <linux/fb.h>
#include "libavutil/log.h"
#include "libavutil/mem.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include "libavutil/pixdesc.h"
#include "libavformat/avformat.h"
#include "libavformat/internal.h"
struct rgb_pixfmt_map_entry {
int bits_per_pixel;
int red_offset, green_offset, blue_offset, alpha_offset;
enum PixelFormat pixfmt;
};
static struct rgb_pixfmt_map_entry rgb_pixfmt_map[] = {
// bpp, red_offset, green_offset, blue_offset, alpha_offset, pixfmt
{ 32, 0, 8, 16, 24, PIX_FMT_RGBA },
{ 32, 16, 8, 0, 24, PIX_FMT_BGRA },
{ 32, 8, 16, 24, 0, PIX_FMT_ARGB },
{ 32, 3, 2, 8, 0, PIX_FMT_ABGR },
{ 24, 0, 8, 16, 0, PIX_FMT_RGB24 },
{ 24, 16, 8, 0, 0, PIX_FMT_BGR24 },
};
static enum PixelFormat get_pixfmt_from_fb_varinfo(struct fb_var_screeninfo *varinfo)
{
int i;
for (i = 0; i < FF_ARRAY_ELEMS(rgb_pixfmt_map); i++) {
struct rgb_pixfmt_map_entry *entry = &rgb_pixfmt_map[i];
if (entry->bits_per_pixel == varinfo->bits_per_pixel &&
entry->red_offset == varinfo->red.offset &&
entry->green_offset == varinfo->green.offset &&
entry->blue_offset == varinfo->blue.offset)
return entry->pixfmt;
}
return PIX_FMT_NONE;
}
typedef struct {
AVClass *class; ///< class for private options
int frame_size; ///< size in bytes of a grabbed frame
AVRational framerate_q; ///< framerate
char *framerate; ///< framerate string set by a private option
int64_t time_frame; ///< time for the next frame to output (in 1/1000000 units)
int fd; ///< framebuffer device file descriptor
int width, height; ///< assumed frame resolution
int frame_linesize; ///< linesize of the output frame, it is assumed to be constant
int bytes_per_pixel;
struct fb_var_screeninfo varinfo; ///< variable info;
struct fb_fix_screeninfo fixinfo; ///< fixed info;
uint8_t *data; ///< framebuffer data
} FBDevContext;
static av_cold int fbdev_read_header(AVFormatContext *avctx)
{
FBDevContext *fbdev = avctx->priv_data;
AVStream *st = NULL;
enum PixelFormat pix_fmt;
int ret, flags = O_RDONLY;
ret = av_parse_video_rate(&fbdev->framerate_q, fbdev->framerate);
if (ret < 0) {
av_log(avctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n", fbdev->framerate);
return ret;
}
if (!(st = avformat_new_stream(avctx, NULL)))
return AVERROR(ENOMEM);
avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in microseconds */
/* NONBLOCK is ignored by the fbdev driver, only set for consistency */
if (avctx->flags & AVFMT_FLAG_NONBLOCK)
flags |= O_NONBLOCK;
if ((fbdev->fd = open(avctx->filename, flags)) == -1) {
ret = AVERROR(errno);
av_log(avctx, AV_LOG_ERROR,
"Could not open framebuffer device '%s': %s\n",
avctx->filename, strerror(ret));
return ret;
}
if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0) {
ret = AVERROR(errno);
av_log(avctx, AV_LOG_ERROR,
"FBIOGET_VSCREENINFO: %s\n", strerror(errno));
goto fail;
}
if (ioctl(fbdev->fd, FBIOGET_FSCREENINFO, &fbdev->fixinfo) < 0) {
ret = AVERROR(errno);
av_log(avctx, AV_LOG_ERROR,
"FBIOGET_FSCREENINFO: %s\n", strerror(errno));
goto fail;
}
pix_fmt = get_pixfmt_from_fb_varinfo(&fbdev->varinfo);
if (pix_fmt == PIX_FMT_NONE) {
ret = AVERROR(EINVAL);
av_log(avctx, AV_LOG_ERROR,
"Framebuffer pixel format not supported.\n");
goto fail;
}
fbdev->width = fbdev->varinfo.xres;
fbdev->height = fbdev->varinfo.yres;
fbdev->bytes_per_pixel = (fbdev->varinfo.bits_per_pixel + 7) >> 3;
fbdev->frame_linesize = fbdev->width * fbdev->bytes_per_pixel;
fbdev->frame_size = fbdev->frame_linesize * fbdev->height;
fbdev->time_frame = AV_NOPTS_VALUE;
fbdev->data = mmap(NULL, fbdev->fixinfo.smem_len, PROT_READ, MAP_SHARED, fbdev->fd, 0);
if (fbdev->data == MAP_FAILED) {
ret = AVERROR(errno);
av_log(avctx, AV_LOG_ERROR, "Error in mmap(): %s\n", strerror(errno));
goto fail;
}
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
st->codec->codec_id = CODEC_ID_RAWVIDEO;
st->codec->width = fbdev->width;
st->codec->height = fbdev->height;
st->codec->pix_fmt = pix_fmt;
st->codec->time_base = (AVRational){fbdev->framerate_q.den, fbdev->framerate_q.num};
st->codec->bit_rate =
fbdev->width * fbdev->height * fbdev->bytes_per_pixel * av_q2d(fbdev->framerate_q) * 8;
av_log(avctx, AV_LOG_INFO,
"w:%d h:%d bpp:%d pixfmt:%s fps:%d/%d bit_rate:%d\n",
fbdev->width, fbdev->height, fbdev->varinfo.bits_per_pixel,
av_pix_fmt_descriptors[pix_fmt].name,
fbdev->framerate_q.num, fbdev->framerate_q.den,
st->codec->bit_rate);
return 0;
fail:
close(fbdev->fd);
return ret;
}
static int fbdev_read_packet(AVFormatContext *avctx, AVPacket *pkt)
{
FBDevContext *fbdev = avctx->priv_data;
int64_t curtime, delay;
struct timespec ts;
int i, ret;
uint8_t *pin, *pout;
if (fbdev->time_frame == AV_NOPTS_VALUE)
fbdev->time_frame = av_gettime();
/* wait based on the frame rate */
curtime = av_gettime();
delay = fbdev->time_frame - curtime;
av_dlog(avctx,
"time_frame:%"PRId64" curtime:%"PRId64" delay:%"PRId64"\n",
fbdev->time_frame, curtime, delay);
if (delay > 0) {
if (avctx->flags & AVFMT_FLAG_NONBLOCK)
return AVERROR(EAGAIN);
ts.tv_sec = delay / 1000000;
ts.tv_nsec = (delay % 1000000) * 1000;
while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
}
/* compute the time of the next frame */
fbdev->time_frame += INT64_C(1000000) / av_q2d(fbdev->framerate_q);
if ((ret = av_new_packet(pkt, fbdev->frame_size)) < 0)
return ret;
/* refresh fbdev->varinfo, visible data position may change at each call */
if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0)
av_log(avctx, AV_LOG_WARNING,
"Error refreshing variable info: %s\n", strerror(errno));
pkt->pts = curtime;
/* compute visible data offset */
pin = fbdev->data + fbdev->bytes_per_pixel * fbdev->varinfo.xoffset +
fbdev->varinfo.yoffset * fbdev->fixinfo.line_length;
pout = pkt->data;
// TODO it'd be nice if the lines were aligned
for (i = 0; i < fbdev->height; i++) {
memcpy(pout, pin, fbdev->frame_linesize);
pin += fbdev->fixinfo.line_length;
pout += fbdev->frame_linesize;
}
return fbdev->frame_size;
}
static av_cold int fbdev_read_close(AVFormatContext *avctx)
{
FBDevContext *fbdev = avctx->priv_data;
munmap(fbdev->data, fbdev->frame_size);
close(fbdev->fd);
return 0;
}
#define OFFSET(x) offsetof(FBDevContext, x)
#define DEC AV_OPT_FLAG_DECODING_PARAM
static const AVOption options[] = {
{ "framerate","", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0, DEC },
{ NULL },
};
static const AVClass fbdev_class = {
.class_name = "fbdev indev",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVInputFormat ff_fbdev_demuxer = {
.name = "fbdev",
.long_name = NULL_IF_CONFIG_SMALL("Linux framebuffer"),
.priv_data_size = sizeof(FBDevContext),
.read_header = fbdev_read_header,
.read_packet = fbdev_read_packet,
.read_close = fbdev_read_close,
.flags = AVFMT_NOFILE,
.priv_class = &fbdev_class,
};
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