/*
  * QTKit input device
  * Copyright (c) 2013 Vadim Kalinsky <vadim@kalinsky.ru>
  *
  * 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
  * QTKit input device
  * @author Vadim Kalinsky <vadim@kalinsky.ru>
  */
 

 #import <QTKit/QTKit.h>

 #include <pthread.h>
 
 #include "libavutil/pixdesc.h"
 #include "libavutil/opt.h"
 #include "libavformat/internal.h"
 #include "libavutil/internal.h"
 #include "libavutil/time.h"
 #include "avdevice.h"
 

 #define QTKIT_TIMEBASE 100

 
 static const AVRational kQTKitTimeBase_q = {
     .num = 1,

     .den = QTKIT_TIMEBASE

 };
 
 typedef struct
 {
     AVClass*        class;
 
     float           frame_rate;
     int             frames_captured;
     int64_t         first_pts;
     pthread_mutex_t frame_lock;
     pthread_cond_t  frame_wait_cond;
     id              qt_delegate;
 

     int             list_devices;
     int             video_device_index;
 

     QTCaptureSession*                 capture_session;
     QTCaptureDecompressedVideoOutput* video_output;
     CVImageBufferRef                  current_frame;
 } CaptureContext;
 
 static void lock_frames(CaptureContext* ctx)
 {
     pthread_mutex_lock(&ctx->frame_lock);
 }
 
 static void unlock_frames(CaptureContext* ctx)
 {
     pthread_mutex_unlock(&ctx->frame_lock);
 }
 
 /** FrameReciever class - delegate for QTCaptureSession
  */
 @interface FFMPEG_FrameReceiver : NSObject
 {
     CaptureContext* _context;
 }
 
 - (id)initWithContext:(CaptureContext*)context;
 
 - (void)captureOutput:(QTCaptureOutput *)captureOutput
   didOutputVideoFrame:(CVImageBufferRef)videoFrame
      withSampleBuffer:(QTSampleBuffer *)sampleBuffer
        fromConnection:(QTCaptureConnection *)connection;
 
 @end
 
 @implementation FFMPEG_FrameReceiver
 
 - (id)initWithContext:(CaptureContext*)context
 {
     if (self = [super init]) {
         _context = context;
     }
     return self;
 }
 
 - (void)captureOutput:(QTCaptureOutput *)captureOutput
   didOutputVideoFrame:(CVImageBufferRef)videoFrame
      withSampleBuffer:(QTSampleBuffer *)sampleBuffer
        fromConnection:(QTCaptureConnection *)connection
 {
     lock_frames(_context);
     if (_context->current_frame != nil) {
         CVBufferRelease(_context->current_frame);
     }
 
     _context->current_frame = CVBufferRetain(videoFrame);
 
     pthread_cond_signal(&_context->frame_wait_cond);
 
     unlock_frames(_context);
 
     ++_context->frames_captured;
 }
 
 @end
 
 static void destroy_context(CaptureContext* ctx)
 {
     [ctx->capture_session stopRunning];
 
     [ctx->capture_session release];
     [ctx->video_output    release];
     [ctx->qt_delegate     release];
 
     ctx->capture_session = NULL;
     ctx->video_output    = NULL;
     ctx->qt_delegate     = NULL;
 
     pthread_mutex_destroy(&ctx->frame_lock);
     pthread_cond_destroy(&ctx->frame_wait_cond);
 
     if (ctx->current_frame)
         CVBufferRelease(ctx->current_frame);
 }
 
 static int qtkit_read_header(AVFormatContext *s)
 {
     NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
 
     CaptureContext* ctx = (CaptureContext*)s->priv_data;
 
     ctx->first_pts = av_gettime();
 
     pthread_mutex_init(&ctx->frame_lock, NULL);
     pthread_cond_init(&ctx->frame_wait_cond, NULL);
 

     // List devices if requested
     if (ctx->list_devices) {
         av_log(ctx, AV_LOG_INFO, "QTKit video devices:\n");
         NSArray *devices = [QTCaptureDevice inputDevicesWithMediaType:QTMediaTypeVideo];
         for (QTCaptureDevice *device in devices) {
             const char *name = [[device localizedDisplayName] UTF8String];
             int index  = [devices indexOfObject:device];
             av_log(ctx, AV_LOG_INFO, "[%d] %s\n", index, name);
         }
         goto fail;
     }
 
     // Find capture device
     QTCaptureDevice *video_device = nil;
 
     // check for device index given in filename
     if (ctx->video_device_index == -1) {
         sscanf(s->filename, "%d", &ctx->video_device_index);
     }
 
     if (ctx->video_device_index >= 0) {
         NSArray *devices = [QTCaptureDevice inputDevicesWithMediaType:QTMediaTypeVideo];
 
         if (ctx->video_device_index >= [devices count]) {
             av_log(ctx, AV_LOG_ERROR, "Invalid device index\n");
             goto fail;
         }
 
         video_device = [devices objectAtIndex:ctx->video_device_index];
     } else if (strncmp(s->filename, "",        1) &&
                strncmp(s->filename, "default", 7)) {
         NSArray *devices = [QTCaptureDevice inputDevicesWithMediaType:QTMediaTypeVideo];
 
         for (QTCaptureDevice *device in devices) {
             if (!strncmp(s->filename, [[device localizedDisplayName] UTF8String], strlen(s->filename))) {
                 video_device = device;
                 break;
             }
         }
         if (!video_device) {
             av_log(ctx, AV_LOG_ERROR, "Video device not found\n");
             goto fail;
         }
     } else {
         video_device = [QTCaptureDevice defaultInputDeviceWithMediaType:QTMediaTypeMuxed];
     }

 
     BOOL success = [video_device open:nil];
 
     // Video capture device not found, looking for QTMediaTypeVideo
     if (!success) {
         video_device = [QTCaptureDevice defaultInputDeviceWithMediaType:QTMediaTypeVideo];
         success      = [video_device open:nil];
 
         if (!success) {
             av_log(s, AV_LOG_ERROR, "No QT capture device found\n");
             goto fail;
         }
     }
 
     NSString* dev_display_name = [video_device localizedDisplayName];
     av_log (s, AV_LOG_DEBUG, "'%s' opened\n", [dev_display_name UTF8String]);
 
     // Initialize capture session
     ctx->capture_session = [[QTCaptureSession alloc] init];
 
     QTCaptureDeviceInput* capture_dev_input = [[[QTCaptureDeviceInput alloc] initWithDevice:video_device] autorelease];
     success = [ctx->capture_session addInput:capture_dev_input error:nil];
 
     if (!success) {
         av_log (s, AV_LOG_ERROR, "Failed to add QT capture device to session\n");
         goto fail;
     }
 
     // Attaching output
     // FIXME: Allow for a user defined pixel format
     ctx->video_output = [[QTCaptureDecompressedVideoOutput alloc] init];
 
     NSDictionary *captureDictionary = [NSDictionary dictionaryWithObject:
                                        [NSNumber numberWithUnsignedInt:kCVPixelFormatType_24RGB]
                                        forKey:(id)kCVPixelBufferPixelFormatTypeKey];
 
     [ctx->video_output setPixelBufferAttributes:captureDictionary];
 
     ctx->qt_delegate = [[FFMPEG_FrameReceiver alloc] initWithContext:ctx];
 
     [ctx->video_output setDelegate:ctx->qt_delegate];
     [ctx->video_output setAutomaticallyDropsLateVideoFrames:YES];
     [ctx->video_output setMinimumVideoFrameInterval:1.0/ctx->frame_rate];
 
     success = [ctx->capture_session addOutput:ctx->video_output error:nil];
 
     if (!success) {
         av_log (s, AV_LOG_ERROR, "can't add video output to capture session\n");
         goto fail;
     }
 
     [ctx->capture_session startRunning];
 
     // Take stream info from the first frame.
     while (ctx->frames_captured < 1) {
         CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0.1, YES);
     }
 
     lock_frames(ctx);
 
     AVStream* stream = avformat_new_stream(s, NULL);
 
     if (!stream) {
         goto fail;
     }
 

     avpriv_set_pts_info(stream, 64, 1, QTKIT_TIMEBASE);

 
     stream->codec->codec_id   = AV_CODEC_ID_RAWVIDEO;
     stream->codec->codec_type = AVMEDIA_TYPE_VIDEO;
     stream->codec->width      = (int)CVPixelBufferGetWidth (ctx->current_frame);
     stream->codec->height     = (int)CVPixelBufferGetHeight(ctx->current_frame);
     stream->codec->pix_fmt    = AV_PIX_FMT_RGB24;
 
     CVBufferRelease(ctx->current_frame);
     ctx->current_frame = nil;
 
     unlock_frames(ctx);
 
     [pool release];
 
     return 0;
 
 fail:
     [pool release];
 
     destroy_context(ctx);
 
     return AVERROR(EIO);
 }
 
 static int qtkit_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     CaptureContext* ctx = (CaptureContext*)s->priv_data;
 
     do {
         lock_frames(ctx);
 
         if (ctx->current_frame != nil) {
             if (av_new_packet(pkt, (int)CVPixelBufferGetDataSize(ctx->current_frame)) < 0) {
                 return AVERROR(EIO);
             }
 
             pkt->pts = pkt->dts = av_rescale_q(av_gettime() - ctx->first_pts, AV_TIME_BASE_Q, kQTKitTimeBase_q);
             pkt->stream_index = 0;
             pkt->flags |= AV_PKT_FLAG_KEY;
 
             CVPixelBufferLockBaseAddress(ctx->current_frame, 0);
 
             void* data = CVPixelBufferGetBaseAddress(ctx->current_frame);
             memcpy(pkt->data, data, pkt->size);
 
             CVPixelBufferUnlockBaseAddress(ctx->current_frame, 0);
             CVBufferRelease(ctx->current_frame);
             ctx->current_frame = nil;
         } else {
             pkt->data = NULL;
             pthread_cond_wait(&ctx->frame_wait_cond, &ctx->frame_lock);
         }
 
         unlock_frames(ctx);
     } while (!pkt->data);
 
     return 0;
 }
 
 static int qtkit_close(AVFormatContext *s)
 {
     CaptureContext* ctx = (CaptureContext*)s->priv_data;
 
     destroy_context(ctx);
 
     return 0;
 }
 
 static const AVOption options[] = {
     { "frame_rate", "set frame rate", offsetof(CaptureContext, frame_rate), AV_OPT_TYPE_FLOAT, { .dbl = 30.0 }, 0.1, 30.0, AV_OPT_TYPE_VIDEO_RATE, NULL },

     { "list_devices", "list available devices", offsetof(CaptureContext, list_devices), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, AV_OPT_FLAG_DECODING_PARAM, "list_devices" },
     { "true", "", 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "list_devices" },
     { "false", "", 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "list_devices" },
     { "video_device_index", "select video device by index for devices with same name (starts at 0)", offsetof(CaptureContext, video_device_index), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },

     { NULL },
 };
 
 static const AVClass qtkit_class = {
     .class_name = "QTKit input device",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,

     .category   = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,

 };
 
 AVInputFormat ff_qtkit_demuxer = {
     .name           = "qtkit",
     .long_name      = NULL_IF_CONFIG_SMALL("QTKit input device"),
     .priv_data_size = sizeof(CaptureContext),
     .read_header    = qtkit_read_header,
     .read_packet    = qtkit_read_packet,
     .read_close     = qtkit_close,
     .flags          = AVFMT_NOFILE,
     .priv_class     = &qtkit_class,
 };