From c6f951442efb34dd63e1e00b19bc30447075d5a3 Mon Sep 17 00:00:00 2001 From: Stefano Sabatini Date: Mon, 7 Mar 2011 18:54:52 +0100 Subject: framebuffer device demuxer Signed-off-by: Anton Khirnov --- libavdevice/fbdev.c | 250 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 250 insertions(+) create mode 100644 libavdevice/fbdev.c (limited to 'libavdevice/fbdev.c') diff --git a/libavdevice/fbdev.c b/libavdevice/fbdev.c new file mode 100644 index 0000000000..6b03be4751 --- /dev/null +++ b/libavdevice/fbdev.c @@ -0,0 +1,250 @@ +/* + * Copyright (c) 2011 Stefano Sabatini + * Copyright (c) 2009 Giliard B. de Freitas + * Copyright (C) 2002 Gunnar Monell + * + * 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 also http://linux-fbdev.sourceforge.net/. + */ + +/* #define DEBUG */ + +#include +#include +#include +#include +#include +#include +#include + +#include "libavutil/mem.h" +#include "libavutil/pixdesc.h" +#include "libavformat/avformat.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 { + int frame_size; ///< size in bytes of a grabbed frame + AVRational time_base; ///< time base + int64_t time_frame; ///< time for the next frame to output (in 1/1000000 units) + + int fd; ///< framebuffer device file descriptor + int width, heigth; ///< 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; + +av_cold static int fbdev_read_header(AVFormatContext *avctx, + AVFormatParameters *ap) +{ + FBDevContext *fbdev = avctx->priv_data; + AVStream *st = NULL; + enum PixelFormat pix_fmt; + int ret, flags = O_RDONLY; + + if (!(st = av_new_stream(avctx, 0))) + return AVERROR(ENOMEM); + av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in microseconds */ + + if (ap->time_base.den <= 0) { + av_log(avctx, AV_LOG_ERROR, "Invalid time base %d/%d\n", + ap->time_base.num, ap->time_base.den); + return AVERROR(EINVAL); + } + + /* 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->heigth = 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->heigth; + fbdev->time_base = ap->time_base; + 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->heigth; + st->codec->pix_fmt = pix_fmt; + st->codec->time_base = ap->time_base; + st->codec->bit_rate = + fbdev->width * fbdev->heigth * fbdev->bytes_per_pixel / av_q2d(ap->time_base) * 8; + + av_log(avctx, AV_LOG_INFO, + "w:%d h:%d bpp:%d pixfmt:%s tb:%d/%d bit_rate:%d\n", + fbdev->width, fbdev->heigth, fbdev->varinfo.bits_per_pixel, + av_pix_fmt_descriptors[pix_fmt].name, + ap->time_base.num, ap->time_base.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->time_base); + + 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->heigth; i++) { + memcpy(pout, pin, fbdev->frame_linesize); + pin += fbdev->fixinfo.line_length; + pout += fbdev->frame_linesize; + } + + return fbdev->frame_size; +} + +av_cold static int fbdev_read_close(AVFormatContext *avctx) +{ + FBDevContext *fbdev = avctx->priv_data; + + munmap(fbdev->data, fbdev->frame_size); + close(fbdev->fd); + + return 0; +} + +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, +}; -- cgit v1.2.3