[FFmpeg-devel] [PATCH] avdevice: add fbdev output device
Stefano Sabatini
stefasab at gmail.com
Sun Oct 20 20:32:13 CEST 2013
On date Saturday 2013-10-19 21:38:22 +0200, Lukasz M encoded:
> >
> > > +
> > > +static av_cold int fbdev_write_header(AVFormatContext *h)
> > > +{
> > > + FBDevContext *s = h->priv_data;
> > > + enum AVPixelFormat pix_fmt;
> > > + AVStream *st = NULL;
> > > + int ret, flags = O_RDWR;
> > > +
> > > + for (int i = 0; i < h->nb_streams; i++) {
> > > + if (h->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
> > > + s->stream_index = i;
> > > + st = h->streams[i];
> > > + break;
> > > + }
> > > + }
> > > + if (!st) {
> > > + av_log(h, AV_LOG_ERROR, "No video stream found.\n");
> > > + return AVERROR(EINVAL);
> > > + }
> >
> > You could add a check and an error or warning in case more than one
> > video stream is sent to the device.
> >
>
> Added a warning. Other output devices could also be updated. Each treat
> this problem in different way.
>
>
> > > + uint8_t *pin, *pout;
> > > + enum AVPixelFormat pix_fmt;
> > > + int disp_height;
> > > + int bytes_to_copy;
> > > + int src_line_size = s->width * s->bpp;
> > > +
> > > + if (s->stream_index != pkt->stream_index)
> > > + return 0;
> > > +
> > > + if (ioctl(s->fd, FBIOGET_VSCREENINFO, &s->varinfo) < 0)
> > > + av_log(h, AV_LOG_WARNING,
> > > + "Error refreshing variable info: %s\n", strerror(errno));
> > > +
> > > + pix_fmt = get_pixfmt_from_fb_varinfo(&s->varinfo);
> > > +
> >
> > > + //TODO: add mapping between formats
> >
> > what do you exactly mean (this is useful for the archive)?
>
>
> I edited this comment to "Consider"
> I mean that fbdev_enc require the same pixel format as current
> configuration of system framebuffer, which may vary even for the same
> hardware.
> This means there is few formats that can be valid, but there is only one at
> a time.
> Simple conversions like rgba -> bgra can be done by replacing memcpy with
> copying byte by byte with proper mapping between input and output offsets.
> I guess there is already pixel conversion inside ffmpeg binary and this
> would be second one which is bad and I haven't do that yet, but on other
> hand it may be helpful in some cases.
Definitively it should be avoided, libswscale is meant for such
conversions.
>
> BTW, Wouldn't it be good idea to extend AVOutputFormat with information
> about supported pixel/sample formats?
> That would allow to guess correct formats without user interaction.
Pixel and sample formats are specified (statically) in the codec
description.
>
> Rest of remarks fixed, updated patch in attachment.
> Relevant fixes in new patches.
> From 59594af22c7341d1a31401c638d100d213cb73f4 Mon Sep 17 00:00:00 2001
> From: Lukasz Marek <lukasz.m.luki at gmail.com>
> Date: Wed, 16 Oct 2013 17:18:55 +0200
> Subject: [PATCH 1/4] avdevice: add fbdev output device
>
> Signed-off-by: Lukasz Marek <lukasz.m.luki at gmail.com>
> ---
> Changelog | 1 +
> configure | 1 +
> doc/outdevs.texi | 29 ++++++
> libavdevice/Makefile | 1 +
> libavdevice/alldevices.c | 2 +-
> libavdevice/fbdev_enc.c | 260 ++++++++++++++++++++++++++++++++++++++++++++++
> libavdevice/version.h | 2 +-
> 7 files changed, 294 insertions(+), 2 deletions(-)
> create mode 100644 libavdevice/fbdev_enc.c
>
> diff --git a/Changelog b/Changelog
> index ee58336..e196d8e 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -40,6 +40,7 @@ version <next>
> - dpx parser
> - max_error_rate parameter in ffmpeg
> - PulseAudio output device
> +- Linux framebuffer output device
>
>
> version 2.0:
> diff --git a/configure b/configure
> index 0ea62aa..4110a4a 100755
> --- a/configure
> +++ b/configure
> @@ -2125,6 +2125,7 @@ dshow_indev_extralibs="-lpsapi -lole32 -lstrmiids -luuid"
> dv1394_indev_deps="dv1394"
> dv1394_indev_select="dv_demuxer"
> fbdev_indev_deps="linux_fb_h"
> +fbdev_outdev_deps="linux_fb_h"
> iec61883_indev_deps="libiec61883"
> jack_indev_deps="jack_jack_h sem_timedwait"
> lavfi_indev_deps="avfilter"
> diff --git a/doc/outdevs.texi b/doc/outdevs.texi
> index 55c9110..7fa8a9b 100644
> --- a/doc/outdevs.texi
> +++ b/doc/outdevs.texi
> @@ -104,6 +104,35 @@ ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_dither colors -
> @end example
> @end itemize
>
> + at section fbdev
> +
> +Linux framebuffer output device.
> +
> +The Linux framebuffer is a graphic hardware-independent abstraction
> +layer to show graphics on a computer monitor, typically on the
> +console. It is accessed through a file device node, usually
> + at file{/dev/fb0}.
> +
> +For more detailed information read the file
> +Documentation/fb/framebuffer.txt included in the Linux source tree.
Nit: @file{Documentation/fb/framebuffer.txt}
> +
> + at subsection Options
> + at table @option
> +
> + at item xoffset
> + at item yoffset
> +Set x/y coordinate of top left corner. Default is 0.
> + at end table
> +
> + at subsection Examples
> +Play a file on framebuffer device @file{/dev/fb0}.
> +Required pixel format depends on current framebuffer settings.
> + at example
> +ffmpeg -re -i INPUT -vcodec rawvideo -pix_fmt bgra -f fbdev /dev/fb0
> + at end example
> +
> +See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1).
> +
> @section oss
>
> OSS (Open Sound System) output device.
> diff --git a/libavdevice/Makefile b/libavdevice/Makefile
> index ad959ee..f6f05e5 100644
> --- a/libavdevice/Makefile
> +++ b/libavdevice/Makefile
> @@ -24,6 +24,7 @@ OBJS-$(CONFIG_DSHOW_INDEV) += dshow.o dshow_enummediatypes.o \
> dshow_pin.o dshow_common.o
> OBJS-$(CONFIG_DV1394_INDEV) += dv1394.o
> OBJS-$(CONFIG_FBDEV_INDEV) += fbdev.o
> +OBJS-$(CONFIG_FBDEV_OUTDEV) += fbdev_enc.o
> OBJS-$(CONFIG_IEC61883_INDEV) += iec61883.o
> OBJS-$(CONFIG_JACK_INDEV) += jack_audio.o timefilter.o
> OBJS-$(CONFIG_LAVFI_INDEV) += lavfi.o
> diff --git a/libavdevice/alldevices.c b/libavdevice/alldevices.c
> index 33ce155..5178f30 100644
> --- a/libavdevice/alldevices.c
> +++ b/libavdevice/alldevices.c
> @@ -51,7 +51,7 @@ void avdevice_register_all(void)
> REGISTER_OUTDEV (CACA, caca);
> REGISTER_INDEV (DSHOW, dshow);
> REGISTER_INDEV (DV1394, dv1394);
> - REGISTER_INDEV (FBDEV, fbdev);
> + REGISTER_INOUTDEV(FBDEV, fbdev);
> REGISTER_INDEV (IEC61883, iec61883);
> REGISTER_INDEV (JACK, jack);
> REGISTER_INDEV (LAVFI, lavfi);
> diff --git a/libavdevice/fbdev_enc.c b/libavdevice/fbdev_enc.c
> new file mode 100644
> index 0000000..fa3d4f7
> --- /dev/null
> +++ b/libavdevice/fbdev_enc.c
> @@ -0,0 +1,260 @@
> +/*
> + * 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"
> +
> +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
> + int index; ///< index of a video stream
> + uint8_t *data; ///< framebuffer data
> + int width; ///< width of source video
> + int height; ///< height of source video
> + int bytes_per_pixel; ///< bytes per pixel of source video
> + enum AVPixelFormat pix_fmt; ///< pixel format of source video
> +} FBDevContext;
> +
> +struct rgb_pixfmt_map_entry {
> + int bits_per_pixel;
> + int red_offset, green_offset, blue_offset, alpha_offset;
> + enum AVPixelFormat pixfmt;
> +};
> +
> +static const struct rgb_pixfmt_map_entry rgb_pixfmt_map[] = {
> + // bpp, red_offset, green_offset, blue_offset, alpha_offset, pixfmt
> + { 32, 0, 8, 16, 24, AV_PIX_FMT_RGBA },
> + { 32, 16, 8, 0, 24, AV_PIX_FMT_BGRA },
> + { 32, 8, 16, 24, 0, AV_PIX_FMT_ARGB },
> + { 32, 3, 2, 8, 0, AV_PIX_FMT_ABGR },
> + { 24, 0, 8, 16, 0, AV_PIX_FMT_RGB24 },
> + { 24, 16, 8, 0, 0, AV_PIX_FMT_BGR24 },
> + { 16, 11, 5, 0, 16, AV_PIX_FMT_RGB565 },
> +};
> +
> +static enum AVPixelFormat get_pixfmt_from_fb_varinfo(struct fb_var_screeninfo *varinfo)
> +{
> + int i;
> +
> + for (i = 0; i < FF_ARRAY_ELEMS(rgb_pixfmt_map); i++) {
> + const 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 AV_PIX_FMT_NONE;
> +}
> +
> +static av_cold int fbdev_write_header(AVFormatContext *h)
> +{
> + FBDevContext *fbdev = h->priv_data;
> + enum AVPixelFormat pix_fmt;
> + AVStream *st = NULL;
> + int ret, flags = O_RDWR;
> +
> + for (int i = 0; i < h->nb_streams; i++) {
> + if (h->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
> + if (!st) {
> + fbdev->index = i;
> + st = h->streams[i];
> + } else {
> + av_log(h, AV_LOG_WARNING, "More than one video stream found. First one is used.\n");
> + break;
> + }
> + }
> + }
> + if (!st) {
> + av_log(h, AV_LOG_ERROR, "No video stream found.\n");
> + return AVERROR(EINVAL);
> + }
> +
> + if ((fbdev->fd = avpriv_open(h->filename, flags)) == -1) {
> + ret = AVERROR(errno);
> + av_log(h, AV_LOG_ERROR,
> + "Could not open framebuffer device '%s': %s\n",
> + h->filename, 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 = 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;
> + }
> +
> + fbdev->pix_fmt = st->codec->pix_fmt;
> + fbdev->width = st->codec->width;
> + fbdev->height = st->codec->height;
> + fbdev->bytes_per_pixel = ((st->codec->bits_per_coded_sample + 7) >> 3);
> +
> + 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 pix_fmt;
> + int disp_height;
> + int bytes_to_copy;
> + int src_line_size = fbdev->width * fbdev->bytes_per_pixel;
> +
> + if (fbdev->index != pkt->stream_index)
> + return 0;
> +
> + if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0)
> + av_log(h, AV_LOG_WARNING,
> + "Error refreshing variable info: %s\n", strerror(errno));
> +
> + pix_fmt = get_pixfmt_from_fb_varinfo(&fbdev->varinfo);
Is this supposed to change midstream? Otherwise you could just use
fbdev->pix_fmt.
> +
> + //TODO: Consider mapping between formats
> + if (pix_fmt != fbdev->pix_fmt) {
> + av_log(h, AV_LOG_ERROR, "Pixel format %s is not supported, use %s\n",
> + av_get_pix_fmt_name(fbdev->pix_fmt), av_get_pix_fmt_name(pix_fmt));
> + return AVERROR(EINVAL);
> + }
> +
> + disp_height = FFMIN(fbdev->varinfo.yres, fbdev->height);
> + bytes_to_copy = FFMIN(fbdev->varinfo.xres, fbdev->width) * fbdev->bytes_per_pixel;
> +
> + pin = pkt->data;
> + pout = fbdev->data +
> + fbdev->bytes_per_pixel * fbdev->varinfo.xoffset +
> + fbdev->varinfo.yoffset * fbdev->fixinfo.line_length;
> +
> + if (fbdev->xoffset) {
> + if (fbdev->xoffset < 0) {
> + if (-fbdev->xoffset >= fbdev->width) //nothing to display
> + return 0;
> + bytes_to_copy += fbdev->xoffset * fbdev->bytes_per_pixel;
> + pin -= fbdev->xoffset * fbdev->bytes_per_pixel;
> + }
> + else {
Nit: } else {
here and below
> + int diff = (fbdev->width + fbdev->xoffset) - fbdev->varinfo.xres;
> + if (diff > 0) {
> + if (diff >= fbdev->width) //nothing to display
> + return 0;
> + bytes_to_copy -= diff * fbdev->bytes_per_pixel;
> + }
> + pout += fbdev->bytes_per_pixel * fbdev->xoffset;
> + }
> + }
> +
> + if (fbdev->yoffset) {
> + if (fbdev->yoffset < 0) {
> + if (-fbdev->yoffset >= fbdev->height) //nothing to display
> + return 0;
> + disp_height += fbdev->yoffset;
> + pin -= fbdev->yoffset * src_line_size;
> + }
> + else {
> + int diff = (fbdev->height + fbdev->yoffset) - fbdev->varinfo.yres;
> + if (diff > 0) {
> + if (diff >= fbdev->height) //nothing to display
> + return 0;
> + disp_height -= diff;
> + }
> + pout += fbdev->yoffset * fbdev->fixinfo.line_length;
> + }
> + }
> +
> + for (int 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;
> +}
> +
> +#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,
> +};
> +
> +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,
> + .flags = AVFMT_NOFILE | AVFMT_VARIABLE_FPS | AVFMT_NOTIMESTAMPS,
> + .priv_class = &fbdev_class,
> +};
> diff --git a/libavdevice/version.h b/libavdevice/version.h
> index 5823ab9..4f4ec99 100644
> --- a/libavdevice/version.h
> +++ b/libavdevice/version.h
> @@ -28,7 +28,7 @@
> #include "libavutil/avutil.h"
>
> #define LIBAVDEVICE_VERSION_MAJOR 55
> -#define LIBAVDEVICE_VERSION_MINOR 4
> +#define LIBAVDEVICE_VERSION_MINOR 5
> #define LIBAVDEVICE_VERSION_MICRO 100
>
> #define LIBAVDEVICE_VERSION_INT AV_VERSION_INT(LIBAVDEVICE_VERSION_MAJOR, \
> --
> 1.7.10.4
>
LGTM otherwise, thanks.
--
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