//
// ZoneMinder Ffmpeg Camera Class Implementation, $Date: 2009-01-16 12:18:50 +0000 (Fri, 16 Jan 2009) $, $Revision: 2713 $
// Copyright (C) 2001-2008 Philip Coombes
// 
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
// 
// This program 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 General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
// 

#include "zm.h"

#if HAVE_LIBAVFORMAT

#include "zm_ffmpeg_camera.h"

FfmpegCamera::FfmpegCamera( int p_id, const std::string &p_path, int p_width, int p_height, int p_colours, int p_brightness, int p_contrast, int p_hue, int p_colour, bool p_capture ) :
    Camera( p_id, FFMPEG_SRC, p_width, p_height, p_colours, p_brightness, p_contrast, p_hue, p_colour, p_capture ),
    mPath( p_path )
{
	if ( capture )
	{
		Initialise();
	}

    mFormatContext = NULL;
    mVideoStreamId = -1;
    mCodecContext = NULL;
    mCodec = NULL;
    mConvertContext = NULL;
    mRawFrame = NULL;
    mFrame = NULL;
}

FfmpegCamera::~FfmpegCamera()
{
    av_freep( &mFrame );
    av_freep( &mRawFrame );
    
    if ( mConvertContext )
    {
        sws_freeContext( mConvertContext );
        mConvertContext = NULL;
    }
    if ( mCodecContext )
    {
       avcodec_close( mCodecContext );
       mCodecContext = NULL; // Freed by av_close_input_file
    }
    if ( mFormatContext )
    {
        av_close_input_file( mFormatContext );
        mFormatContext = NULL;
    }

	if ( capture )
	{
		Terminate();
	}
}

void FfmpegCamera::Initialise()
{
	int max_size = width*height*colours;

	mBuffer.size( max_size );

    if ( logDebugging() )
        av_log_set_level( AV_LOG_DEBUG ); 
    else
        av_log_set_level( AV_LOG_QUIET ); 

    av_register_all();
}

void FfmpegCamera::Terminate()
{
}

int FfmpegCamera::PrimeCapture()
{
    Info( "Priming capture from %s", mPath.c_str() );

    // Open the input, not necessarily a file
    if ( av_open_input_file( &mFormatContext, mPath.c_str(), NULL, 0, NULL ) !=0 )
        Fatal( "Unable to open input %s due to: %s", mPath.c_str(), strerror(errno) );

    // Locate stream info from input
    if ( av_find_stream_info( mFormatContext ) < 0 )
        Fatal( "Unable to find stream info from %s due to: %s", mPath.c_str(), strerror(errno) );
    
    // Find first video stream present
    mVideoStreamId = -1;
    for ( int i=0; i < mFormatContext->nb_streams; i++ )
    {
#if LIBAVUTIL_VERSION_INT >= AV_VERSION_INT(51,2,1)
        if ( mFormatContext->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO )
#else
        if ( mFormatContext->streams[i]->codec->codec_type == CODEC_TYPE_VIDEO )
#endif
        {
            mVideoStreamId = i;
            break;
        }
    }
    if ( mVideoStreamId == -1 )
        Fatal( "Unable to locate video stream in %s", mPath.c_str() );

    mCodecContext = mFormatContext->streams[mVideoStreamId]->codec;

    // Try and get the codec from the codec context
    if ( (mCodec = avcodec_find_decoder( mCodecContext->codec_id )) == NULL )
        Fatal( "Can't find codec for video stream from %s", mPath.c_str() );

    // Open the codec
    if ( avcodec_open( mCodecContext, mCodec ) < 0 )
        Fatal( "Unable to open codec for video stream from %s", mPath.c_str() );

    // Allocate space for the native video frame
    mRawFrame = avcodec_alloc_frame();

    // Allocate space for the converted video frame
    mFrame = avcodec_alloc_frame();

    // Determine required buffer size and allocate buffer
    int pictureSize = avpicture_get_size( PIX_FMT_RGB24, mCodecContext->width, mCodecContext->height );
    mBuffer.size( pictureSize );
    
    avpicture_fill( (AVPicture *)mFrame, (unsigned char *)mBuffer, PIX_FMT_RGB24, mCodecContext->width, mCodecContext->height);

#if HAVE_LIBSWSCALE
    if ( (mConvertContext = sws_getCachedContext( mConvertContext, mCodecContext->width, mCodecContext->height, mCodecContext->pix_fmt, width, height, PIX_FMT_RGB24, SWS_BICUBIC, NULL, NULL, NULL )) == NULL )
        Fatal( "Unable to create conversion context for %s", mPath.c_str() );
#else // HAVE_LIBSWSCALE
    Fatal( "You must compile ffmpeg with the --enable-swscale option to use ffmpeg cameras" );
#endif // HAVE_LIBSWSCALE

    return( 0 );
}

int FfmpegCamera::PreCapture()
{
    // Nothing to do here
    return( 0 );
}

int FfmpegCamera::Capture( Image &image )
{
    static int frameCount = 0;
    AVPacket packet;
    int frameComplete = false;
    while ( !frameComplete )
    {
        int avResult = av_read_frame( mFormatContext, &packet );
        if ( avResult < 0 )
        {
            Error( "Unable to read packet from stream %d: error %d", packet.stream_index, avResult );
            return( -1 );
        }
        Debug( 5, "Got packet from stream %d", packet.stream_index );
        if ( packet.stream_index == mVideoStreamId )
        {
            if ( avcodec_decode_video2( mCodecContext, mRawFrame, &frameComplete, &packet ) < 0 )
                Fatal( "Unable to decode frame at frame %d", frameCount );

            Debug( 3, "Decoded video packet at frame %d", frameCount );

            if ( frameComplete )
            {
                Debug( 1, "Got frame %d", frameCount );

#if HAVE_LIBSWSCALE
                if ( sws_scale( mConvertContext, mRawFrame->data, mRawFrame->linesize, 0, mCodecContext->height, mFrame->data, mFrame->linesize ) < 0 )
                    Fatal( "Unable to convert raw format %d to RGB at frame %d", mCodecContext->pix_fmt, frameCount );
#else // HAVE_LIBSWSCALE
    Fatal( "You must compile ffmpeg with the --enable-swscale option to use ffmpeg cameras" );
#endif // HAVE_LIBSWSCALE
 
                image.Assign( mCodecContext->width, mCodecContext->height, colours, (unsigned char *)mFrame->data[0] );

                frameCount++;
            }
        }
        av_free_packet( &packet );
    }
    return (0);
}

int FfmpegCamera::PostCapture()
{
    // Nothing to do here
    return( 0 );
}

#endif // HAVE_LIBAVFORMAT