Libav 0.7.1
libavdevice/fbdev.c
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00001 /*
00002  * Copyright (c) 2011 Stefano Sabatini
00003  * Copyright (c) 2009 Giliard B. de Freitas <giliarde@gmail.com>
00004  * Copyright (C) 2002 Gunnar Monell <gmo@linux.nu>
00005  *
00006  * This file is part of Libav.
00007  *
00008  * Libav is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * Libav is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with Libav; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00030 /* #define DEBUG */
00031 
00032 #include <unistd.h>
00033 #include <fcntl.h>
00034 #include <sys/ioctl.h>
00035 #include <sys/time.h>
00036 #include <sys/mman.h>
00037 #include <time.h>
00038 #include <linux/fb.h>
00039 
00040 #include "libavutil/log.h"
00041 #include "libavutil/mem.h"
00042 #include "libavutil/opt.h"
00043 #include "libavutil/parseutils.h"
00044 #include "libavutil/pixdesc.h"
00045 #include "libavformat/avformat.h"
00046 
00047 struct rgb_pixfmt_map_entry {
00048     int bits_per_pixel;
00049     int red_offset, green_offset, blue_offset, alpha_offset;
00050     enum PixelFormat pixfmt;
00051 };
00052 
00053 static struct rgb_pixfmt_map_entry rgb_pixfmt_map[] = {
00054     // bpp, red_offset,  green_offset, blue_offset, alpha_offset, pixfmt
00055     {  32,       0,           8,          16,           24,   PIX_FMT_RGBA  },
00056     {  32,      16,           8,           0,           24,   PIX_FMT_BGRA  },
00057     {  32,       8,          16,          24,            0,   PIX_FMT_ARGB  },
00058     {  32,       3,           2,           8,            0,   PIX_FMT_ABGR  },
00059     {  24,       0,           8,          16,            0,   PIX_FMT_RGB24 },
00060     {  24,      16,           8,           0,            0,   PIX_FMT_BGR24 },
00061 };
00062 
00063 static enum PixelFormat get_pixfmt_from_fb_varinfo(struct fb_var_screeninfo *varinfo)
00064 {
00065     int i;
00066 
00067     for (i = 0; i < FF_ARRAY_ELEMS(rgb_pixfmt_map); i++) {
00068         struct rgb_pixfmt_map_entry *entry = &rgb_pixfmt_map[i];
00069         if (entry->bits_per_pixel == varinfo->bits_per_pixel &&
00070             entry->red_offset     == varinfo->red.offset     &&
00071             entry->green_offset   == varinfo->green.offset   &&
00072             entry->blue_offset    == varinfo->blue.offset)
00073             return entry->pixfmt;
00074     }
00075 
00076     return PIX_FMT_NONE;
00077 }
00078 
00079 typedef struct {
00080     AVClass *class;          
00081     int frame_size;          
00082     AVRational fps;          
00083     char *framerate;         
00084     int64_t time_frame;      
00085 
00086     int fd;                  
00087     int width, heigth;       
00088     int frame_linesize;      
00089     int bytes_per_pixel;
00090 
00091     struct fb_var_screeninfo varinfo; 
00092     struct fb_fix_screeninfo fixinfo; 
00093 
00094     uint8_t *data;           
00095 } FBDevContext;
00096 
00097 av_cold static int fbdev_read_header(AVFormatContext *avctx,
00098                                      AVFormatParameters *ap)
00099 {
00100     FBDevContext *fbdev = avctx->priv_data;
00101     AVStream *st = NULL;
00102     enum PixelFormat pix_fmt;
00103     int ret, flags = O_RDONLY;
00104 
00105     ret = av_parse_video_rate(&fbdev->fps, fbdev->framerate);
00106     if (ret < 0) {
00107         av_log(avctx, AV_LOG_ERROR, "Couldn't parse framerate.\n");
00108         return ret;
00109     }
00110 #if FF_API_FORMAT_PARAMETERS
00111     if (ap->time_base.num)
00112         fbdev->fps = (AVRational){ap->time_base.den, ap->time_base.num};
00113 #endif
00114 
00115     if (!(st = av_new_stream(avctx, 0)))
00116         return AVERROR(ENOMEM);
00117     av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in microseconds */
00118 
00119     /* NONBLOCK is ignored by the fbdev driver, only set for consistency */
00120     if (avctx->flags & AVFMT_FLAG_NONBLOCK)
00121         flags |= O_NONBLOCK;
00122 
00123     if ((fbdev->fd = open(avctx->filename, flags)) == -1) {
00124         ret = AVERROR(errno);
00125         av_log(avctx, AV_LOG_ERROR,
00126                "Could not open framebuffer device '%s': %s\n",
00127                avctx->filename, strerror(ret));
00128         return ret;
00129     }
00130 
00131     if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0) {
00132         ret = AVERROR(errno);
00133         av_log(avctx, AV_LOG_ERROR,
00134                "FBIOGET_VSCREENINFO: %s\n", strerror(errno));
00135         goto fail;
00136     }
00137 
00138     if (ioctl(fbdev->fd, FBIOGET_FSCREENINFO, &fbdev->fixinfo) < 0) {
00139         ret = AVERROR(errno);
00140         av_log(avctx, AV_LOG_ERROR,
00141                "FBIOGET_FSCREENINFO: %s\n", strerror(errno));
00142         goto fail;
00143     }
00144 
00145     pix_fmt = get_pixfmt_from_fb_varinfo(&fbdev->varinfo);
00146     if (pix_fmt == PIX_FMT_NONE) {
00147         ret = AVERROR(EINVAL);
00148         av_log(avctx, AV_LOG_ERROR,
00149                "Framebuffer pixel format not supported.\n");
00150         goto fail;
00151     }
00152 
00153     fbdev->width           = fbdev->varinfo.xres;
00154     fbdev->heigth          = fbdev->varinfo.yres;
00155     fbdev->bytes_per_pixel = (fbdev->varinfo.bits_per_pixel + 7) >> 3;
00156     fbdev->frame_linesize  = fbdev->width * fbdev->bytes_per_pixel;
00157     fbdev->frame_size      = fbdev->frame_linesize * fbdev->heigth;
00158     fbdev->time_frame      = AV_NOPTS_VALUE;
00159     fbdev->data = mmap(NULL, fbdev->fixinfo.smem_len, PROT_READ, MAP_SHARED, fbdev->fd, 0);
00160     if (fbdev->data == MAP_FAILED) {
00161         ret = AVERROR(errno);
00162         av_log(avctx, AV_LOG_ERROR, "Error in mmap(): %s\n", strerror(errno));
00163         goto fail;
00164     }
00165 
00166     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00167     st->codec->codec_id   = CODEC_ID_RAWVIDEO;
00168     st->codec->width      = fbdev->width;
00169     st->codec->height     = fbdev->heigth;
00170     st->codec->pix_fmt    = pix_fmt;
00171     st->codec->time_base  = (AVRational){fbdev->fps.den, fbdev->fps.num};
00172     st->codec->bit_rate   =
00173         fbdev->width * fbdev->heigth * fbdev->bytes_per_pixel * av_q2d(fbdev->fps) * 8;
00174 
00175     av_log(avctx, AV_LOG_INFO,
00176            "w:%d h:%d bpp:%d pixfmt:%s fps:%d/%d bit_rate:%d\n",
00177            fbdev->width, fbdev->heigth, fbdev->varinfo.bits_per_pixel,
00178            av_pix_fmt_descriptors[pix_fmt].name,
00179            fbdev->fps.num, fbdev->fps.den,
00180            st->codec->bit_rate);
00181     return 0;
00182 
00183 fail:
00184     close(fbdev->fd);
00185     return ret;
00186 }
00187 
00188 static int fbdev_read_packet(AVFormatContext *avctx, AVPacket *pkt)
00189 {
00190     FBDevContext *fbdev = avctx->priv_data;
00191     int64_t curtime, delay;
00192     struct timespec ts;
00193     int i, ret;
00194     uint8_t *pin, *pout;
00195 
00196     if (fbdev->time_frame == AV_NOPTS_VALUE)
00197         fbdev->time_frame = av_gettime();
00198 
00199     /* wait based on the frame rate */
00200     curtime = av_gettime();
00201     delay = fbdev->time_frame - curtime;
00202     av_dlog(avctx,
00203             "time_frame:%"PRId64" curtime:%"PRId64" delay:%"PRId64"\n",
00204             fbdev->time_frame, curtime, delay);
00205     if (delay > 0) {
00206         if (avctx->flags & AVFMT_FLAG_NONBLOCK)
00207             return AVERROR(EAGAIN);
00208         ts.tv_sec  =  delay / 1000000;
00209         ts.tv_nsec = (delay % 1000000) * 1000;
00210         while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
00211     }
00212     /* compute the time of the next frame */
00213     fbdev->time_frame += INT64_C(1000000) / av_q2d(fbdev->fps);
00214 
00215     if ((ret = av_new_packet(pkt, fbdev->frame_size)) < 0)
00216         return ret;
00217 
00218     /* refresh fbdev->varinfo, visible data position may change at each call */
00219     if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0)
00220         av_log(avctx, AV_LOG_WARNING,
00221                "Error refreshing variable info: %s\n", strerror(errno));
00222 
00223     pkt->pts = curtime;
00224 
00225     /* compute visible data offset */
00226     pin = fbdev->data + fbdev->bytes_per_pixel * fbdev->varinfo.xoffset +
00227                         fbdev->varinfo.yoffset * fbdev->fixinfo.line_length;
00228     pout = pkt->data;
00229 
00230     // TODO it'd be nice if the lines were aligned
00231     for (i = 0; i < fbdev->heigth; i++) {
00232         memcpy(pout, pin, fbdev->frame_linesize);
00233         pin  += fbdev->fixinfo.line_length;
00234         pout += fbdev->frame_linesize;
00235     }
00236 
00237     return fbdev->frame_size;
00238 }
00239 
00240 av_cold static int fbdev_read_close(AVFormatContext *avctx)
00241 {
00242     FBDevContext *fbdev = avctx->priv_data;
00243 
00244     munmap(fbdev->data, fbdev->frame_size);
00245     close(fbdev->fd);
00246 
00247     return 0;
00248 }
00249 
00250 #define OFFSET(x) offsetof(FBDevContext, x)
00251 #define DEC AV_OPT_FLAG_DECODING_PARAM
00252 static const AVOption options[] = {
00253     { "framerate","", OFFSET(framerate), FF_OPT_TYPE_STRING, {.str = "25"}, 0, 0, DEC },
00254     { NULL },
00255 };
00256 
00257 static const AVClass fbdev_class = {
00258     .class_name = "fbdev indev",
00259     .item_name  = av_default_item_name,
00260     .option     = options,
00261     .version    = LIBAVUTIL_VERSION_INT,
00262 };
00263 
00264 AVInputFormat ff_fbdev_demuxer = {
00265     .name           = "fbdev",
00266     .long_name      = NULL_IF_CONFIG_SMALL("Linux framebuffer"),
00267     .priv_data_size = sizeof(FBDevContext),
00268     .read_header    = fbdev_read_header,
00269     .read_packet    = fbdev_read_packet,
00270     .read_close     = fbdev_read_close,
00271     .flags          = AVFMT_NOFILE,
00272     .priv_class     = &fbdev_class,
00273 };