/*
  * Linux video grab interface

  * Copyright (c) 2000,2001 Fabrice Bellard

  *

  * 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 "avdevice.h"
 

 #undef __STRICT_ANSI__ //workaround due to broken kernel headers

 #include "config.h"

 #include "libavutil/rational.h"

 #include "libavutil/imgutils.h"

 #include "libavutil/log.h"
 #include "libavutil/opt.h"

 #include "libavformat/internal.h"

 #include "libavcodec/dsputil.h"

 #include <unistd.h>
 #include <fcntl.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
 #include <sys/time.h>

 #define _LINUX_TIME_H 1
 #include <linux/videodev.h>

 #include <time.h>

 #include "avdevice.h"

 
 typedef struct {

     AVClass *class;

     int fd;
     int frame_format; /* see VIDEO_PALETTE_xxx */
     int use_mmap;

     AVRational time_base;

     int64_t time_frame;

     int frame_size;

     struct video_capability video_cap;
     struct video_audio audio_saved;

     struct video_window video_win;

     uint8_t *video_buf;

     struct video_mbuf gb_buffers;
     struct video_mmap gb_buf;
     int gb_frame;

     int standard;

 } VideoData;
 

 static const struct {

     int palette;
     int depth;

     enum AVPixelFormat pix_fmt;

 } video_formats [] = {

     {.palette = VIDEO_PALETTE_YUV420P, .depth = 12, .pix_fmt = AV_PIX_FMT_YUV420P },
     {.palette = VIDEO_PALETTE_YUV422,  .depth = 16, .pix_fmt = AV_PIX_FMT_YUYV422 },
     {.palette = VIDEO_PALETTE_UYVY,    .depth = 16, .pix_fmt = AV_PIX_FMT_UYVY422 },
     {.palette = VIDEO_PALETTE_YUYV,    .depth = 16, .pix_fmt = AV_PIX_FMT_YUYV422 },

     /* NOTE: v4l uses BGR24, not RGB24 */

     {.palette = VIDEO_PALETTE_RGB24,   .depth = 24, .pix_fmt = AV_PIX_FMT_BGR24   },
     {.palette = VIDEO_PALETTE_RGB565,  .depth = 16, .pix_fmt = AV_PIX_FMT_BGR565  },
     {.palette = VIDEO_PALETTE_GREY,    .depth = 8,  .pix_fmt = AV_PIX_FMT_GRAY8   },

 };
 
 

 static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)

 {

     VideoData *s = s1->priv_data;

     AVStream *st;

     int video_fd;

     int desired_palette, desired_depth;

     struct video_tuner tuner;

     struct video_audio audio;

     struct video_picture pict;

     int j;

     int vformat_num = FF_ARRAY_ELEMS(video_formats);

     av_log(s1, AV_LOG_WARNING, "V4L input device is deprecated and will be removed in the next release.");
 

     if (ap->time_base.den <= 0) {
         av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);

         return -1;

     }

     s->time_base = ap->time_base;

     s->video_win.width = ap->width;
     s->video_win.height = ap->height;

     st = avformat_new_stream(s1, NULL);

     if (!st)

         return AVERROR(ENOMEM);

     avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */

     video_fd = open(s1->filename, O_RDWR);

     if (video_fd < 0) {

         av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno));

         goto fail;

     }

     if (ioctl(video_fd, VIDIOCGCAP, &s->video_cap) < 0) {

         av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno));

         goto fail;
     }
 

     if (!(s->video_cap.type & VID_TYPE_CAPTURE)) {

         av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n");

         goto fail;
     }

     /* no values set, autodetect them */
     if (s->video_win.width <= 0 || s->video_win.height <= 0) {
         if (ioctl(video_fd, VIDIOCGWIN, &s->video_win, sizeof(s->video_win)) < 0) {
             av_log(s1, AV_LOG_ERROR, "VIDIOCGWIN: %s\n", strerror(errno));
             goto fail;
         }
     }
 

     if(av_image_check_size(s->video_win.width, s->video_win.height, 0, s1) < 0)

         return -1;
 

     desired_palette = -1;

     desired_depth = -1;

     for (j = 0; j < vformat_num; j++) {
         if (ap->pix_fmt == video_formats[j].pix_fmt) {
             desired_palette = video_formats[j].palette;
             desired_depth = video_formats[j].depth;
             break;
         }

     }

 
     /* set tv standard */

     if (!ioctl(video_fd, VIDIOCGTUNER, &tuner)) {
         tuner.mode = s->standard;

         ioctl(video_fd, VIDIOCSTUNER, &tuner);

     }

     /* unmute audio */

     audio.audio = 0;

     ioctl(video_fd, VIDIOCGAUDIO, &audio);

     memcpy(&s->audio_saved, &audio, sizeof(audio));

     audio.flags &= ~VIDEO_AUDIO_MUTE;
     ioctl(video_fd, VIDIOCSAUDIO, &audio);
 

     ioctl(video_fd, VIDIOCGPICT, &pict);

     av_dlog(s1, "v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",
             pict.colour, pict.hue, pict.brightness, pict.contrast, pict.whiteness);

     /* try to choose a suitable video format */
     pict.palette = desired_palette;

     pict.depth= desired_depth;

     if (desired_palette == -1 || ioctl(video_fd, VIDIOCSPICT, &pict) < 0) {

         for (j = 0; j < vformat_num; j++) {
             pict.palette = video_formats[j].palette;
             pict.depth = video_formats[j].depth;
             if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict))
                 break;

         }

         if (j >= vformat_num)
             goto fail1;

     }
 

     if (ioctl(video_fd, VIDIOCGMBUF, &s->gb_buffers) < 0) {

         /* try to use read based access */
         int val;
 

         s->video_win.x = 0;
         s->video_win.y = 0;
         s->video_win.chromakey = -1;
         s->video_win.flags = 0;

         if (ioctl(video_fd, VIDIOCSWIN, s->video_win) < 0) {
             av_log(s1, AV_LOG_ERROR, "VIDIOCSWIN: %s\n", strerror(errno));
             goto fail;
         }

 
         s->frame_format = pict.palette;
 
         val = 1;

         if (ioctl(video_fd, VIDIOCCAPTURE, &val) < 0) {
             av_log(s1, AV_LOG_ERROR, "VIDIOCCAPTURE: %s\n", strerror(errno));
             goto fail;
         }

         s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;

         s->use_mmap = 0;
     } else {

         s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_SHARED, video_fd, 0);

         if ((unsigned char*)-1 == s->video_buf) {

             s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_PRIVATE, video_fd, 0);

             if ((unsigned char*)-1 == s->video_buf) {

                 av_log(s1, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));

                 goto fail;
             }

         }

         s->gb_frame = 0;

         s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;

         /* start to grab the first frame */

         s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames;

         s->gb_buf.height = s->video_win.height;
         s->gb_buf.width = s->video_win.width;

         s->gb_buf.format = pict.palette;
 

         if (ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {

             if (errno != EAGAIN) {
             fail1:

                 av_log(s1, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));

             } else {

                 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not receive any video signal\n");

             }
             goto fail;
         }

         for (j = 1; j < s->gb_buffers.frames; j++) {
           s->gb_buf.frame = j;
           ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);
         }

         s->frame_format = s->gb_buf.format;

         s->use_mmap = 1;
     }
 

     for (j = 0; j < vformat_num; j++) {
         if (s->frame_format == video_formats[j].palette) {

             s->frame_size = s->video_win.width * s->video_win.height * video_formats[j].depth / 8;

             st->codec->pix_fmt = video_formats[j].pix_fmt;
             break;
         }

     }

 
     if (j >= vformat_num)
         goto fail;
 

     s->fd = video_fd;

     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

     st->codec->codec_id = AV_CODEC_ID_RAWVIDEO;

     st->codec->width = s->video_win.width;
     st->codec->height = s->video_win.height;

     st->codec->time_base = s->time_base;

     st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;

     return 0;
  fail:

     if (video_fd >= 0)
         close(video_fd);

     return AVERROR(EIO);

 }
 

 static int v4l_mm_read_picture(VideoData *s, uint8_t *buf)

 {

     uint8_t *ptr;

     while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 &&
            (errno == EAGAIN || errno == EINTR));
 
     ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame];
     memcpy(buf, ptr, s->frame_size);
 

     /* Setup to capture the next frame */

     s->gb_buf.frame = s->gb_frame;

     if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {

         if (errno == EAGAIN)

             av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n");

         else

             av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));

         return AVERROR(EIO);

     }

 
     /* This is now the grabbing frame */

     s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames;

     return s->frame_size;

 }
 

 static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt)

 {

     VideoData *s = s1->priv_data;

     int64_t curtime, delay;

     struct timespec ts;

 
     /* Calculate the time of the next frame */

     s->time_frame += INT64_C(1000000);

 
     /* wait based on the frame rate */

     for(;;) {

         curtime = av_gettime();

         delay = s->time_frame * s->time_base.num / s->time_base.den - curtime;

         if (delay <= 0) {

             if (delay < INT64_C(-1000000) * s->time_base.num / s->time_base.den) {

                 /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */

                 s->time_frame += INT64_C(1000000);

             }

             break;

         }

         ts.tv_sec = delay / 1000000;
         ts.tv_nsec = (delay % 1000000) * 1000;
         nanosleep(&ts, NULL);
     }
 
     if (av_new_packet(pkt, s->frame_size) < 0)

         return AVERROR(EIO);

     pkt->pts = curtime;

     /* read one frame */

     if (s->use_mmap) {

         return v4l_mm_read_picture(s, pkt->data);

     } else {

         if (read(s->fd, pkt->data, pkt->size) != pkt->size)

             return AVERROR(EIO);

         return s->frame_size;

     }
 }
 

 static int grab_read_close(AVFormatContext *s1)

 {

     VideoData *s = s1->priv_data;

 
     if (s->use_mmap)

         munmap(s->video_buf, s->gb_buffers.size);

     /* mute audio. we must force it because the BTTV driver does not
        return its state correctly */
     s->audio_saved.flags |= VIDEO_AUDIO_MUTE;
     ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved);

     close(s->fd);
     return 0;
 }
 

 static const AVOption options[] = {

     { "standard", "", offsetof(VideoData, standard), AV_OPT_TYPE_INT, {.i64 = VIDEO_MODE_NTSC}, VIDEO_MODE_PAL, VIDEO_MODE_NTSC, AV_OPT_FLAG_DECODING_PARAM, "standard" },

     { "PAL",   "", 0, AV_OPT_TYPE_CONST, {.i64 = VIDEO_MODE_PAL},   0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
     { "SECAM", "", 0, AV_OPT_TYPE_CONST, {.i64 = VIDEO_MODE_SECAM}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
     { "NTSC",  "", 0, AV_OPT_TYPE_CONST, {.i64 = VIDEO_MODE_NTSC},  0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },

     { NULL },
 };
 
 static const AVClass v4l_class = {
     .class_name = "V4L indev",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 

 AVInputFormat ff_v4l_demuxer = {

     .name           = "video4linux,v4l",

     .long_name      = NULL_IF_CONFIG_SMALL("Video4Linux device grab"),
     .priv_data_size = sizeof(VideoData),
     .read_header    = grab_read_header,
     .read_packet    = grab_read_packet,
     .read_close     = grab_read_close,
     .flags          = AVFMT_NOFILE,
     .priv_class     = &v4l_class,

 };