/*
  * Video4Linux2 grab interface

  * Copyright (c) 2000,2001 Fabrice Bellard
  * Copyright (c) 2006 Luca Abeni

  *
  * Part of this file is based on the V4L2 video capture example
  * (http://v4l2spec.bytesex.org/v4l2spec/capture.c)
  *
  * Thanks to Michael Niedermayer for providing the mapping between
  * V4L2_PIX_FMT_* and PIX_FMT_*
  *
  *

  * 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
  */

 #undef __STRICT_ANSI__ //workaround due to broken kernel headers

 #include "config.h"

 #include "libavformat/avformat.h"

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

 #if HAVE_SYS_VIDEOIO_H

 #include <sys/videoio.h>
 #else

 #include <asm/types.h>
 #include <linux/videodev2.h>

 #endif

 #include <time.h>

 #include <strings.h>

 
 static const int desired_video_buffers = 256;
 
 enum io_method {
     io_read,
     io_mmap,
     io_userptr
 };
 
 struct video_data {
     int fd;
     int frame_format; /* V4L2_PIX_FMT_* */
     enum io_method io_method;
     int width, height;
     int frame_size;
     int top_field_first;
 
     int buffers;
     void **buf_start;
     unsigned int *buf_len;
 };
 

 struct buff_data {
     int index;
     int fd;
 };
 

 struct fmt_map {
     enum PixelFormat ff_fmt;
     int32_t v4l2_fmt;
 };
 
 static struct fmt_map fmt_conversion_table[] = {
     {
         .ff_fmt = PIX_FMT_YUV420P,
         .v4l2_fmt = V4L2_PIX_FMT_YUV420,
     },
     {
         .ff_fmt = PIX_FMT_YUV422P,
         .v4l2_fmt = V4L2_PIX_FMT_YUV422P,
     },
     {

         .ff_fmt = PIX_FMT_YUYV422,

         .v4l2_fmt = V4L2_PIX_FMT_YUYV,
     },
     {
         .ff_fmt = PIX_FMT_UYVY422,
         .v4l2_fmt = V4L2_PIX_FMT_UYVY,
     },
     {
         .ff_fmt = PIX_FMT_YUV411P,
         .v4l2_fmt = V4L2_PIX_FMT_YUV411P,
     },
     {
         .ff_fmt = PIX_FMT_YUV410P,
         .v4l2_fmt = V4L2_PIX_FMT_YUV410,
     },
     {

         .ff_fmt = PIX_FMT_RGB555,
         .v4l2_fmt = V4L2_PIX_FMT_RGB555,
     },
     {
         .ff_fmt = PIX_FMT_RGB565,
         .v4l2_fmt = V4L2_PIX_FMT_RGB565,
     },
     {

         .ff_fmt = PIX_FMT_BGR24,
         .v4l2_fmt = V4L2_PIX_FMT_BGR24,
     },
     {
         .ff_fmt = PIX_FMT_RGB24,
         .v4l2_fmt = V4L2_PIX_FMT_RGB24,
     },
     {

         .ff_fmt = PIX_FMT_BGRA,

         .v4l2_fmt = V4L2_PIX_FMT_BGR32,
     },
     {
         .ff_fmt = PIX_FMT_GRAY8,
         .v4l2_fmt = V4L2_PIX_FMT_GREY,
     },
 };
 

 static int device_open(AVFormatContext *ctx, uint32_t *capabilities)

 {
     struct v4l2_capability cap;
     int fd;
     int res;

     int flags = O_RDWR;

     if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
         flags |= O_NONBLOCK;
     }
     fd = open(ctx->filename, flags, 0);

     if (fd < 0) {

         av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",

                  ctx->filename, strerror(errno));

 
         return -1;
     }
 
     res = ioctl(fd, VIDIOC_QUERYCAP, &cap);

     // ENOIOCTLCMD definition only availble on __KERNEL__
     if (res < 0 && errno == 515)
     {

         av_log(ctx, AV_LOG_ERROR, "QUERYCAP not implemented, probably V4L device but not supporting V4L2\n");

         close(fd);

 
         return -1;
     }

     if (res < 0) {

         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",

                  strerror(errno));

         close(fd);

 
         return -1;
     }
     if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {

         av_log(ctx, AV_LOG_ERROR, "Not a video capture device\n");

         close(fd);

 
         return -1;
     }
     *capabilities = cap.capabilities;
 
     return fd;
 }
 

 static int device_init(AVFormatContext *ctx, int *width, int *height, int pix_fmt)

 {

     struct video_data *s = ctx->priv_data;
     int fd = s->fd;

     struct v4l2_format fmt;

     int res;

 
     memset(&fmt, 0, sizeof(struct v4l2_format));
     fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

     fmt.fmt.pix.width = *width;
     fmt.fmt.pix.height = *height;

     fmt.fmt.pix.pixelformat = pix_fmt;
     fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;

     res = ioctl(fd, VIDIOC_S_FMT, &fmt);
     if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {

         av_log(ctx, AV_LOG_INFO, "The V4L2 driver changed the video from %dx%d to %dx%d\n", *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);

         *width = fmt.fmt.pix.width;
         *height = fmt.fmt.pix.height;
     }
 

     if (pix_fmt != fmt.fmt.pix.pixelformat) {
         av_log(ctx, AV_LOG_DEBUG, "The V4L2 driver changed the pixel format from 0x%08X to 0x%08X\n", pix_fmt, fmt.fmt.pix.pixelformat);
         res = -1;
     }
 

     return res;

 }
 
 static int first_field(int fd)
 {
     int res;
     v4l2_std_id std;
 
     res = ioctl(fd, VIDIOC_G_STD, &std);
     if (res < 0) {
         return 0;
     }
     if (std & V4L2_STD_NTSC) {
         return 0;
     }
 
     return 1;
 }
 
 static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt)
 {
     int i;
 

     for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {

         if (fmt_conversion_table[i].ff_fmt == pix_fmt) {
             return fmt_conversion_table[i].v4l2_fmt;
         }
     }
 
     return 0;
 }
 
 static enum PixelFormat fmt_v4l2ff(uint32_t pix_fmt)
 {
     int i;
 

     for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {

         if (fmt_conversion_table[i].v4l2_fmt == pix_fmt) {
             return fmt_conversion_table[i].ff_fmt;
         }
     }
 

     return PIX_FMT_NONE;

 }
 

 static int mmap_init(AVFormatContext *ctx)

 {

     struct video_data *s = ctx->priv_data;

     struct v4l2_requestbuffers req;
     int i, res;
 
     memset(&req, 0, sizeof(struct v4l2_requestbuffers));
     req.count = desired_video_buffers;
     req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
     req.memory = V4L2_MEMORY_MMAP;
     res = ioctl (s->fd, VIDIOC_REQBUFS, &req);
     if (res < 0) {
         if (errno == EINVAL) {

             av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");

         } else {

             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");

         }
 
         return -1;
     }
 
     if (req.count < 2) {

         av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");

 
         return -1;
     }
     s->buffers = req.count;
     s->buf_start = av_malloc(sizeof(void *) * s->buffers);
     if (s->buf_start == NULL) {

         av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");

 
         return -1;
     }
     s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
     if (s->buf_len == NULL) {

         av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");

         av_free(s->buf_start);
 
         return -1;
     }
 
     for (i = 0; i < req.count; i++) {
         struct v4l2_buffer buf;
 
         memset(&buf, 0, sizeof(struct v4l2_buffer));
         buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
         buf.memory = V4L2_MEMORY_MMAP;
         buf.index = i;
         res = ioctl (s->fd, VIDIOC_QUERYBUF, &buf);
         if (res < 0) {

             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");

 
             return -1;
         }
 
         s->buf_len[i] = buf.length;
         if (s->buf_len[i] < s->frame_size) {

             av_log(ctx, AV_LOG_ERROR, "Buffer len [%d] = %d != %d\n", i, s->buf_len[i], s->frame_size);

 
             return -1;
         }
         s->buf_start[i] = mmap (NULL, buf.length,
                         PROT_READ | PROT_WRITE, MAP_SHARED, s->fd, buf.m.offset);
         if (s->buf_start[i] == MAP_FAILED) {

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

 
             return -1;
         }
     }
 
     return 0;
 }
 

 static int read_init(AVFormatContext *ctx)

 {
     return -1;
 }
 

 static void mmap_release_buffer(AVPacket *pkt)
 {
     struct v4l2_buffer buf;
     int res, fd;
     struct buff_data *buf_descriptor = pkt->priv;
 

     if (pkt->data == NULL) {
          return;
     }
 

     memset(&buf, 0, sizeof(struct v4l2_buffer));
     buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
     buf.memory = V4L2_MEMORY_MMAP;
     buf.index = buf_descriptor->index;
     fd = buf_descriptor->fd;
     av_free(buf_descriptor);
 
     res = ioctl (fd, VIDIOC_QBUF, &buf);
     if (res < 0) {
         av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
     }
     pkt->data = NULL;
     pkt->size = 0;
 }
 
 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)

 {

     struct video_data *s = ctx->priv_data;

     struct v4l2_buffer buf;

     struct buff_data *buf_descriptor;

     int res;
 
     memset(&buf, 0, sizeof(struct v4l2_buffer));
     buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
     buf.memory = V4L2_MEMORY_MMAP;
 
     /* FIXME: Some special treatment might be needed in case of loss of signal... */

     while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));

     if (res < 0) {

         if (errno == EAGAIN) {
             pkt->size = 0;
 
             return AVERROR(EAGAIN);
         }

         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", strerror(errno));

 
         return -1;
     }
     assert (buf.index < s->buffers);

     if (buf.bytesused != s->frame_size) {

         av_log(ctx, AV_LOG_ERROR, "The v4l2 frame is %d bytes, but %d bytes are expected\n", buf.bytesused, s->frame_size);

 
         return -1;
     }
 

     /* Image is at s->buff_start[buf.index] */

     pkt->data= s->buf_start[buf.index];
     pkt->size = buf.bytesused;
     pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
     pkt->destruct = mmap_release_buffer;
     buf_descriptor = av_malloc(sizeof(struct buff_data));
     if (buf_descriptor == NULL) {
         /* Something went wrong... Since av_malloc() failed, we cannot even
          * allocate a buffer for memcopying into it
          */
         av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
         res = ioctl (s->fd, VIDIOC_QBUF, &buf);

 
         return -1;
     }

     buf_descriptor->fd = s->fd;
     buf_descriptor->index = buf.index;
     pkt->priv = buf_descriptor;

 
     return s->buf_len[buf.index];
 }
 

 static int read_frame(AVFormatContext *ctx, AVPacket *pkt)

 {
     return -1;
 }
 

 static int mmap_start(AVFormatContext *ctx)

 {

     struct video_data *s = ctx->priv_data;

     enum v4l2_buf_type type;
     int i, res;
 
     for (i = 0; i < s->buffers; i++) {
         struct v4l2_buffer buf;
 
         memset(&buf, 0, sizeof(struct v4l2_buffer));
         buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
         buf.memory = V4L2_MEMORY_MMAP;
         buf.index  = i;
 
         res = ioctl (s->fd, VIDIOC_QBUF, &buf);
         if (res < 0) {

             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));

 
             return -1;
         }
     }
 
     type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
     res = ioctl (s->fd, VIDIOC_STREAMON, &type);
     if (res < 0) {

         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", strerror(errno));

 
         return -1;
     }
 
     return 0;
 }
 
 static void mmap_close(struct video_data *s)
 {
     enum v4l2_buf_type type;
     int i;
 
     type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
     /* We do not check for the result, because we could
      * not do anything about it anyway...
      */
     ioctl(s->fd, VIDIOC_STREAMOFF, &type);
     for (i = 0; i < s->buffers; i++) {
         munmap(s->buf_start[i], s->buf_len[i]);
     }
     av_free(s->buf_start);
     av_free(s->buf_len);
 }
 

 static int v4l2_set_parameters( AVFormatContext *s1, AVFormatParameters *ap )
 {
     struct video_data *s = s1->priv_data;
     struct v4l2_input input;
     struct v4l2_standard standard;
     int i;
 

     if(ap->channel>=0) {

         /* set tv video input */
         memset (&input, 0, sizeof (input));
         input.index = ap->channel;
         if(ioctl (s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
             av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");

             return AVERROR(EIO);

         }

         av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
                ap->channel, input.name);
         if(ioctl (s->fd, VIDIOC_S_INPUT, &input.index) < 0 ) {
             av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set input(%d) failed\n",
                    ap->channel);

             return AVERROR(EIO);

         }

     }

     if(ap->standard) {

         av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
                ap->standard );
         /* set tv standard */
         memset (&standard, 0, sizeof (standard));
         for(i=0;;i++) {
             standard.index = i;
             if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
                 av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
                        ap->standard);

                 return AVERROR(EIO);

             }
 
             if(!strcasecmp(standard.name, ap->standard)) {
                 break;
             }
         }
 
         av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s, id: %"PRIu64"\n",

                ap->standard, (uint64_t)standard.id);

         if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {

             av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
                    ap->standard);

             return AVERROR(EIO);

         }

     }

 
     return 0;
 }
 

 static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)
 {
     struct video_data *s = s1->priv_data;
     AVStream *st;
     int width, height;

     int res;

     uint32_t desired_format, capabilities;
 

     if (ap->width <= 0 || ap->height <= 0) {
         av_log(s1, AV_LOG_ERROR, "Wrong size (%dx%d)\n", ap->width, ap->height);
         return -1;
     }

 
     width = ap->width;
     height = ap->height;
 

     if(avcodec_check_dimensions(s1, ap->width, ap->height) < 0)

         return -1;
 
     st = av_new_stream(s1, 0);
     if (!st) {

         return AVERROR(ENOMEM);

     }
     av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
 
     s->width = width;
     s->height = height;
 
     capabilities = 0;

     s->fd = device_open(s1, &capabilities);

     if (s->fd < 0) {

         return AVERROR(EIO);

     }

     av_log(s1, AV_LOG_INFO, "[%d]Capabilities: %x\n", s->fd, capabilities);

 
     desired_format = fmt_ff2v4l(ap->pix_fmt);

     if (desired_format == 0 || (device_init(s1, &width, &height, desired_format) < 0)) {

         int i, done;
 
         done = 0; i = 0;
         while (!done) {
             desired_format = fmt_conversion_table[i].v4l2_fmt;

             if (device_init(s1, &width, &height, desired_format) < 0) {

                 desired_format = 0;
                 i++;
             } else {
                done = 1;
             }

             if (i == FF_ARRAY_ELEMS(fmt_conversion_table)) {

                done = 1;
             }
         }
     }
     if (desired_format == 0) {
         av_log(s1, AV_LOG_ERROR, "Cannot find a proper format.\n");
         close(s->fd);
 

         return AVERROR(EIO);

     }
     s->frame_format = desired_format;
 

     if( v4l2_set_parameters( s1, ap ) < 0 )

         return AVERROR(EIO);

     st->codec->pix_fmt = fmt_v4l2ff(desired_format);
     s->frame_size = avpicture_get_size(st->codec->pix_fmt, width, height);
     if (capabilities & V4L2_CAP_STREAMING) {
         s->io_method = io_mmap;

         res = mmap_init(s1);

         if (res == 0) {

             res = mmap_start(s1);

         }

     } else {
         s->io_method = io_read;

         res = read_init(s1);

     }
     if (res < 0) {
         close(s->fd);
 

         return AVERROR(EIO);

     }
     s->top_field_first = first_field(s->fd);
 
     st->codec->codec_type = CODEC_TYPE_VIDEO;
     st->codec->codec_id = CODEC_ID_RAWVIDEO;
     st->codec->width = width;
     st->codec->height = height;

     st->codec->time_base.den = ap->time_base.den;
     st->codec->time_base.num = ap->time_base.num;

     st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
 
     return 0;
 }
 
 static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
 {
     struct video_data *s = s1->priv_data;
     int res;
 
     if (s->io_method == io_mmap) {

         av_init_packet(pkt);
         res = mmap_read_frame(s1, pkt);

     } else if (s->io_method == io_read) {

         if (av_new_packet(pkt, s->frame_size) < 0)

             return AVERROR(EIO);

 
         res = read_frame(s1, pkt);

     } else {

         return AVERROR(EIO);

     }
     if (res < 0) {

         return res;

     }
 
     if (s1->streams[0]->codec->coded_frame) {
         s1->streams[0]->codec->coded_frame->interlaced_frame = 1;
         s1->streams[0]->codec->coded_frame->top_field_first = s->top_field_first;
     }
 
     return s->frame_size;
 }
 
 static int v4l2_read_close(AVFormatContext *s1)
 {
     struct video_data *s = s1->priv_data;
 
     if (s->io_method == io_mmap) {
         mmap_close(s);
     }
 
     close(s->fd);
     return 0;
 }
 

 AVInputFormat v4l2_demuxer = {

     "video4linux2",

     NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),

     sizeof(struct video_data),
     NULL,
     v4l2_read_header,
     v4l2_read_packet,
     v4l2_read_close,
     .flags = AVFMT_NOFILE,
 };