/*
  * Copyright (c) 2013 Jeff Moguillansky
  *
  * 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
  */
 
 /**
  * @file
  * XVideo output device
  *
  * TODO:
  * - add support to more formats
  */
 
 #include <X11/Xlib.h>
 #include <X11/extensions/Xv.h>
 #include <X11/extensions/XShm.h>

 #include <X11/extensions/Xvlib.h>

 #include <sys/shm.h>
 
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"

 #include "libavutil/imgutils.h"

 #include "libavformat/internal.h"

 #include "avdevice.h"
 
 typedef struct {
     AVClass *class;
     GC gc;
 
     Window window;

     int64_t window_id;

     char *window_title;
     int window_width, window_height;
     int window_x, window_y;

     int dest_x, dest_y;          /**< display area position */
     unsigned int dest_w, dest_h; /**< display area dimensions */

 
     Display* display;
     char *display_name;
 
     XvImage* yuv_image;

     enum AVPixelFormat image_format;

     int image_width, image_height;
     XShmSegmentInfo yuv_shminfo;
     int xv_port;

     Atom wm_delete_message;

 } XVContext;
 

 typedef struct XVTagFormatMap
 {
     int tag;
     enum AVPixelFormat format;
 } XVTagFormatMap;
 

 static const XVTagFormatMap tag_codec_map[] = {

     { MKTAG('I','4','2','0'), AV_PIX_FMT_YUV420P },
     { MKTAG('U','Y','V','Y'), AV_PIX_FMT_UYVY422 },
     { MKTAG('Y','U','Y','2'), AV_PIX_FMT_YUYV422 },
     { 0,                      AV_PIX_FMT_NONE }
 };
 
 static int xv_get_tag_from_format(enum AVPixelFormat format)
 {

     const XVTagFormatMap *m = tag_codec_map;

     int i;
     for (i = 0; m->tag; m = &tag_codec_map[++i]) {
         if (m->format == format)
             return m->tag;
     }
     return 0;
 }
 

 static int xv_write_trailer(AVFormatContext *s)
 {
     XVContext *xv = s->priv_data;
     if (xv->display) {
         XShmDetach(xv->display, &xv->yuv_shminfo);
         if (xv->yuv_image)
             shmdt(xv->yuv_image->data);
         XFree(xv->yuv_image);
         if (xv->gc)
             XFreeGC(xv->display, xv->gc);
         XCloseDisplay(xv->display);
     }
     return 0;
 }
 

 static int xv_write_header(AVFormatContext *s)
 {
     XVContext *xv = s->priv_data;
     unsigned int num_adaptors;
     XvAdaptorInfo *ai;
     XvImageFormatValues *fv;

     XColor fgcolor;
     XWindowAttributes window_attrs;

     int num_formats = 0, j, tag, ret;

     AVCodecContext *encctx = s->streams[0]->codec;
 
     if (   s->nb_streams > 1
         || encctx->codec_type != AVMEDIA_TYPE_VIDEO
         || encctx->codec_id   != AV_CODEC_ID_RAWVIDEO) {
         av_log(s, AV_LOG_ERROR, "Only supports one rawvideo stream\n");
         return AVERROR(EINVAL);
     }
 

     if (!(tag = xv_get_tag_from_format(encctx->pix_fmt))) {
         av_log(s, AV_LOG_ERROR,
                "Unsupported pixel format '%s', only yuv420p, uyvy422, yuyv422 are currently supported\n",
                av_get_pix_fmt_name(encctx->pix_fmt));
         return AVERROR_PATCHWELCOME;
     }
     xv->image_format = encctx->pix_fmt;
 

     xv->display = XOpenDisplay(xv->display_name);
     if (!xv->display) {
         av_log(s, AV_LOG_ERROR, "Could not open the X11 display '%s'\n", xv->display_name);
         return AVERROR(EINVAL);
     }
 
     xv->image_width  = encctx->width;
     xv->image_height = encctx->height;
     if (!xv->window_width && !xv->window_height) {

         AVRational sar = encctx->sample_aspect_ratio;

         xv->window_width  = encctx->width;
         xv->window_height = encctx->height;

         if (sar.num) {
             if (sar.num > sar.den)
                 xv->window_width = av_rescale(xv->window_width, sar.num, sar.den);
             if (sar.num < sar.den)
                 xv->window_height = av_rescale(xv->window_height, sar.den, sar.num);
         }

     }

     if (!xv->window_id) {

         xv->window = XCreateSimpleWindow(xv->display, DefaultRootWindow(xv->display),
                                          xv->window_x, xv->window_y,
                                          xv->window_width, xv->window_height,
                                          0, 0, 0);
         if (!xv->window_title) {
             if (!(xv->window_title = av_strdup(s->filename))) {
                 ret = AVERROR(ENOMEM);
                 goto fail;
             }

         }

         XStoreName(xv->display, xv->window, xv->window_title);

         xv->wm_delete_message = XInternAtom(xv->display, "WM_DELETE_WINDOW", False);
         XSetWMProtocols(xv->display, xv->window, &xv->wm_delete_message, 1);

         XMapWindow(xv->display, xv->window);

     } else
         xv->window = xv->window_id;

     if (XvQueryAdaptors(xv->display, DefaultRootWindow(xv->display), &num_adaptors, &ai) != Success) {
         ret = AVERROR_EXTERNAL;
         goto fail;
     }

     if (!num_adaptors) {
         av_log(s, AV_LOG_ERROR, "No X-Video adaptors present\n");
         return AVERROR(ENODEV);
     }

     xv->xv_port = ai[0].base_id;

     XvFreeAdaptorInfo(ai);

 
     fv = XvListImageFormats(xv->display, xv->xv_port, &num_formats);

     if (!fv) {
         ret = AVERROR_EXTERNAL;
         goto fail;
     }

     for (j = 0; j < num_formats; j++) {

         if (fv[j].id == tag) {

             break;
         }
     }
     XFree(fv);
 
     if (j >= num_formats) {
         av_log(s, AV_LOG_ERROR,

                "Device does not support pixel format %s, aborting\n",
                av_get_pix_fmt_name(encctx->pix_fmt));

         ret = AVERROR(EINVAL);
         goto fail;

     }
 
     xv->gc = XCreateGC(xv->display, xv->window, 0, 0);
     xv->image_width  = encctx->width;
     xv->image_height = encctx->height;

     xv->yuv_image = XvShmCreateImage(xv->display, xv->xv_port, tag, 0,

                                      xv->image_width, xv->image_height, &xv->yuv_shminfo);
     xv->yuv_shminfo.shmid = shmget(IPC_PRIVATE, xv->yuv_image->data_size,
                                    IPC_CREAT | 0777);
     xv->yuv_shminfo.shmaddr = (char *)shmat(xv->yuv_shminfo.shmid, 0, 0);
     xv->yuv_image->data = xv->yuv_shminfo.shmaddr;
     xv->yuv_shminfo.readOnly = False;
 
     XShmAttach(xv->display, &xv->yuv_shminfo);
     XSync(xv->display, False);
     shmctl(xv->yuv_shminfo.shmid, IPC_RMID, 0);
 

     XGetWindowAttributes(xv->display, xv->window, &window_attrs);
     fgcolor.red = fgcolor.green = fgcolor.blue = 0;
     fgcolor.flags = DoRed | DoGreen | DoBlue;
     XAllocColor(xv->display, window_attrs.colormap, &fgcolor);
     XSetForeground(xv->display, xv->gc, fgcolor.pixel);
     //force display area recalculation at first frame
     xv->window_width = xv->window_height = 0;
 

     return 0;

   fail:
     xv_write_trailer(s);
     return ret;

 }
 

 static void compute_display_area(AVFormatContext *s)
 {
     XVContext *xv = s->priv_data;
     AVRational sar, dar; /* sample and display aspect ratios */
     AVStream *st = s->streams[0];
     AVCodecContext *encctx = st->codec;
 
     /* compute overlay width and height from the codec context information */
     sar = st->sample_aspect_ratio.num ? st->sample_aspect_ratio : (AVRational){ 1, 1 };
     dar = av_mul_q(sar, (AVRational){ encctx->width, encctx->height });
 
     /* we suppose the screen has a 1/1 sample aspect ratio */
     /* fit in the window */
     if (av_cmp_q(dar, (AVRational){ xv->dest_w, xv->dest_h }) > 0) {
         /* fit in width */
         xv->dest_y = xv->dest_h;
         xv->dest_x = 0;
         xv->dest_h = av_rescale(xv->dest_w, dar.den, dar.num);
         xv->dest_y -= xv->dest_h;
         xv->dest_y /= 2;
     } else {
         /* fit in height */
         xv->dest_x = xv->dest_w;
         xv->dest_y = 0;
         xv->dest_w = av_rescale(xv->dest_h, dar.num, dar.den);
         xv->dest_x -= xv->dest_w;
         xv->dest_x /= 2;
     }
 }
 

 static int xv_repaint(AVFormatContext *s)

 {
     XVContext *xv = s->priv_data;
     XWindowAttributes window_attrs;
 
     XGetWindowAttributes(xv->display, xv->window, &window_attrs);

     if (window_attrs.width != xv->window_width || window_attrs.height != xv->window_height) {
         XRectangle rect[2];
         xv->dest_w = window_attrs.width;
         xv->dest_h = window_attrs.height;
         compute_display_area(s);
         if (xv->dest_x) {
             rect[0].width  = rect[1].width  = xv->dest_x;
             rect[0].height = rect[1].height = window_attrs.height;
             rect[0].y      = rect[1].y      = 0;
             rect[0].x = 0;
             rect[1].x = xv->dest_w + xv->dest_x;
             XFillRectangles(xv->display, xv->window, xv->gc, rect, 2);
         }
         if (xv->dest_y) {
             rect[0].width  = rect[1].width  = window_attrs.width;
             rect[0].height = rect[1].height = xv->dest_y;
             rect[0].x      = rect[1].x      = 0;
             rect[0].y = 0;
             rect[1].y = xv->dest_h + xv->dest_y;
             XFillRectangles(xv->display, xv->window, xv->gc, rect, 2);
         }
     }
 

     if (XvShmPutImage(xv->display, xv->xv_port, xv->window, xv->gc,

                       xv->yuv_image, 0, 0, xv->image_width, xv->image_height,
                       xv->dest_x, xv->dest_y, xv->dest_w, xv->dest_h, True) != Success) {

         av_log(s, AV_LOG_ERROR, "Could not copy image to XV shared memory buffer\n");
         return AVERROR_EXTERNAL;
     }
     return 0;
 }
 

 static int write_picture(AVFormatContext *s, AVPicture *pict)
 {
     XVContext *xv = s->priv_data;
     XvImage *img = xv->yuv_image;
     uint8_t *data[3] = {
         img->data + img->offsets[0],
         img->data + img->offsets[1],
         img->data + img->offsets[2]
     };

 
     /* Check messages. Window might get closed. */
     if (!xv->window_id) {
         XEvent event;
         while (XPending(xv->display)) {
             XNextEvent(xv->display, &event);

             if (event.type == ClientMessage && event.xclient.data.l[0] == xv->wm_delete_message) {

                 av_log(xv, AV_LOG_DEBUG, "Window close event.\n");
                 return AVERROR(EPIPE);
             }
         }
     }
 

     av_image_copy(data, img->pitches, (const uint8_t **)pict->data, pict->linesize,
                   xv->image_format, img->width, img->height);
     return xv_repaint(s);
 }
 

 static int xv_write_packet(AVFormatContext *s, AVPacket *pkt)
 {
     AVPicture pict;
     AVCodecContext *ctx = s->streams[0]->codec;
 
     avpicture_fill(&pict, pkt->data, ctx->pix_fmt, ctx->width, ctx->height);
     return write_picture(s, &pict);
 }
 
 static int xv_write_frame(AVFormatContext *s, int stream_index, AVFrame **frame,
                           unsigned flags)
 {
     /* xv_write_header() should have accepted only supported formats */
     if ((flags & AV_WRITE_UNCODED_FRAME_QUERY))
         return 0;
     return write_picture(s, (AVPicture *)*frame);
 }
 

 static int xv_control_message(AVFormatContext *s, int type, void *data, size_t data_size)
 {
     switch(type) {
     case AV_APP_TO_DEV_WINDOW_REPAINT:
         return xv_repaint(s);
     default:
         break;
     }
     return AVERROR(ENOSYS);
 }
 

 #define OFFSET(x) offsetof(XVContext, x)
 static const AVOption options[] = {
     { "display_name", "set display name",       OFFSET(display_name), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },

     { "window_id",    "set existing window id", OFFSET(window_id),    AV_OPT_TYPE_INT64,  {.i64 = 0 }, 0, INT64_MAX, AV_OPT_FLAG_ENCODING_PARAM },

     { "window_size",  "set window forced size", OFFSET(window_width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
     { "window_title", "set window title",       OFFSET(window_title), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
     { "window_x",     "set window x offset",    OFFSET(window_x),     AV_OPT_TYPE_INT,    {.i64 = 0 }, -INT_MAX, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
     { "window_y",     "set window y offset",    OFFSET(window_y),     AV_OPT_TYPE_INT,    {.i64 = 0 }, -INT_MAX, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
     { NULL }
 
 };
 
 static const AVClass xv_class = {
     .class_name = "xvideo outdev",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,

     .category   = AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT,

 };
 
 AVOutputFormat ff_xv_muxer = {
     .name           = "xv",
     .long_name      = NULL_IF_CONFIG_SMALL("XV (XVideo) output device"),
     .priv_data_size = sizeof(XVContext),
     .audio_codec    = AV_CODEC_ID_NONE,
     .video_codec    = AV_CODEC_ID_RAWVIDEO,
     .write_header   = xv_write_header,
     .write_packet   = xv_write_packet,

     .write_uncoded_frame = xv_write_frame,

     .write_trailer  = xv_write_trailer,

     .control_message = xv_control_message,

     .flags          = AVFMT_NOFILE | AVFMT_VARIABLE_FPS | AVFMT_NOTIMESTAMPS,
     .priv_class     = &xv_class,
 };