/*
  * Copyright (c) 2011 Stefano Sabatini
  *
  * 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
  * libSDL output device
  */
 
 #include <SDL.h>
 #include "libavutil/avstring.h"
 #include "libavutil/opt.h"
 #include "libavutil/parseutils.h"
 #include "libavutil/pixdesc.h"
 #include "avdevice.h"
 
 typedef struct {
     AVClass *class;
     SDL_Surface *surface;
     SDL_Overlay *overlay;
     char *window_title;
     char *icon_title;

     int window_width,  window_height;  /**< size of the window */
     int overlay_width, overlay_height; /**< size of the video in the window */

     int overlay_x, overlay_y;

     int overlay_fmt;
     int sdl_was_already_inited;
 } SDLContext;
 

 static const struct sdl_overlay_pix_fmt_entry {

     enum PixelFormat pix_fmt; int overlay_fmt;
 } sdl_overlay_pix_fmt_map[] = {
     { PIX_FMT_YUV420P, SDL_IYUV_OVERLAY },
     { PIX_FMT_YUYV422, SDL_YUY2_OVERLAY },
     { PIX_FMT_UYVY422, SDL_UYVY_OVERLAY },
     { PIX_FMT_NONE,    0                },
 };
 
 static int sdl_write_trailer(AVFormatContext *s)
 {
     SDLContext *sdl = s->priv_data;
 
     av_freep(&sdl->window_title);
     av_freep(&sdl->icon_title);
 
     if (sdl->overlay) {
         SDL_FreeYUVOverlay(sdl->overlay);
         sdl->overlay = NULL;
     }
     if (!sdl->sdl_was_already_inited)
         SDL_Quit();
 
     return 0;
 }
 
 static int sdl_write_header(AVFormatContext *s)
 {
     SDLContext *sdl = s->priv_data;
     AVStream *st = s->streams[0];
     AVCodecContext *encctx = st->codec;

     AVRational sar, dar; /* sample and display aspect ratios */

     int i, ret;
 

     if (!sdl->window_title)
         sdl->window_title = av_strdup(s->filename);

     if (!sdl->icon_title)
         sdl->icon_title = av_strdup(sdl->window_title);
 
     if (SDL_WasInit(SDL_INIT_VIDEO)) {
         av_log(s, AV_LOG_ERROR,

                "SDL video subsystem was already inited, aborting\n");

         sdl->sdl_was_already_inited = 1;
         ret = AVERROR(EINVAL);
         goto fail;
     }
 
     if (SDL_Init(SDL_INIT_VIDEO) != 0) {
         av_log(s, AV_LOG_ERROR, "Unable to initialize SDL: %s\n", SDL_GetError());
         ret = AVERROR(EINVAL);
         goto fail;
     }
 
     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");
         ret = AVERROR(EINVAL);
         goto fail;
     }
 
     for (i = 0; sdl_overlay_pix_fmt_map[i].pix_fmt != PIX_FMT_NONE; i++) {
         if (sdl_overlay_pix_fmt_map[i].pix_fmt == encctx->pix_fmt) {
             sdl->overlay_fmt = sdl_overlay_pix_fmt_map[i].overlay_fmt;
             break;
         }
     }
 
     if (!sdl->overlay_fmt) {
         av_log(s, AV_LOG_ERROR,

                "Unsupported pixel format '%s', choose one of yuv420p, yuyv422, or uyvy422\n",

                av_get_pix_fmt_name(encctx->pix_fmt));
         ret = AVERROR(EINVAL);
         goto fail;
     }
 
     /* 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 */

     if (sdl->window_width && sdl->window_height) {
         /* fit in the window */
         if (av_cmp_q(dar, (AVRational){ sdl->window_width, sdl->window_height }) > 0) {
             /* fit in width */
             sdl->overlay_width  = sdl->window_width;
             sdl->overlay_height = av_rescale(sdl->overlay_width, dar.den, dar.num);
         } else {
             /* fit in height */
             sdl->overlay_height = sdl->window_height;
             sdl->overlay_width  = av_rescale(sdl->overlay_height, dar.num, dar.den);
         }
     } else {
         if (sar.num > sar.den) {
             sdl->overlay_width  = encctx->width;
             sdl->overlay_height = av_rescale(sdl->overlay_width, dar.den, dar.num);
         } else {
             sdl->overlay_height = encctx->height;
             sdl->overlay_width  = av_rescale(sdl->overlay_height, dar.num, dar.den);
         }

         sdl->window_width  = sdl->overlay_width;
         sdl->window_height = sdl->overlay_height;
     }

     sdl->overlay_x = (sdl->window_width  - sdl->overlay_width ) / 2;
     sdl->overlay_y = (sdl->window_height - sdl->overlay_height) / 2;

 
     SDL_WM_SetCaption(sdl->window_title, sdl->icon_title);
     sdl->surface = SDL_SetVideoMode(sdl->window_width, sdl->window_height,
                                     24, SDL_SWSURFACE);
     if (!sdl->surface) {
         av_log(s, AV_LOG_ERROR, "Unable to set video mode: %s\n", SDL_GetError());
         ret = AVERROR(EINVAL);
         goto fail;
     }
 

     sdl->overlay = SDL_CreateYUVOverlay(encctx->width, encctx->height,

                                         sdl->overlay_fmt, sdl->surface);

     if (!sdl->overlay || sdl->overlay->pitches[0] < encctx->width) {

         av_log(s, AV_LOG_ERROR,

                "SDL does not support an overlay with size of %dx%d pixels\n",

                encctx->width, encctx->height);

         ret = AVERROR(EINVAL);
         goto fail;
     }
 

     av_log(s, AV_LOG_VERBOSE, "w:%d h:%d fmt:%s sar:%d/%d -> w:%d h:%d\n",

            encctx->width, encctx->height, av_get_pix_fmt_name(encctx->pix_fmt), sar.num, sar.den,
            sdl->overlay_width, sdl->overlay_height);

     return 0;
 
 fail:
     sdl_write_trailer(s);
     return ret;
 }
 
 static int sdl_write_packet(AVFormatContext *s, AVPacket *pkt)
 {
     SDLContext *sdl = s->priv_data;
     AVCodecContext *encctx = s->streams[0]->codec;

     SDL_Rect rect = { sdl->overlay_x, sdl->overlay_y, sdl->overlay_width, sdl->overlay_height };

     AVPicture pict;
     int i;
 
     avpicture_fill(&pict, pkt->data, encctx->pix_fmt, encctx->width, encctx->height);
 
     SDL_FillRect(sdl->surface, &sdl->surface->clip_rect,
                  SDL_MapRGB(sdl->surface->format, 0, 0, 0));
     SDL_LockYUVOverlay(sdl->overlay);
     for (i = 0; i < 3; i++) {
         sdl->overlay->pixels [i] = pict.data    [i];
         sdl->overlay->pitches[i] = pict.linesize[i];
     }
     SDL_DisplayYUVOverlay(sdl->overlay, &rect);
     SDL_UnlockYUVOverlay(sdl->overlay);
 

     SDL_UpdateRect(sdl->surface, rect.x, rect.y, rect.w, rect.h);

 
     return 0;
 }
 
 #define OFFSET(x) offsetof(SDLContext,x)
 
 static const AVOption options[] = {

     { "window_title", "set SDL window title",           OFFSET(window_title), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
     { "icon_title",   "set SDL iconified window title", OFFSET(icon_title)  , AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
     { "window_size",  "set SDL window forced size",     OFFSET(window_width), AV_OPT_TYPE_IMAGE_SIZE,{.str=NULL}, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },

     { NULL },
 };
 
 static const AVClass sdl_class = {
     .class_name = "sdl outdev",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 
 AVOutputFormat ff_sdl_muxer = {
     .name           = "sdl",
     .long_name      = NULL_IF_CONFIG_SMALL("SDL output device"),
     .priv_data_size = sizeof(SDLContext),

     .audio_codec    = AV_CODEC_ID_NONE,
     .video_codec    = AV_CODEC_ID_RAWVIDEO,

     .write_header   = sdl_write_header,
     .write_packet   = sdl_write_packet,
     .write_trailer  = sdl_write_trailer,

     .flags          = AVFMT_NOFILE | AVFMT_VARIABLE_FPS | AVFMT_NOTIMESTAMPS,

     .priv_class     = &sdl_class,
 };