FFmpeg/vhook/ppm.c

/*
 * PPM Video Hook 
 * Copyright (c) 2003 Charles Yates
 *
 * This library 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 of the License, or (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <ctype.h>
#include "framehook.h"

/** Bi-directional pipe structure.
*/

typedef struct rwpipe
{
	int pid;
	FILE *reader;
	FILE *writer;
}
rwpipe;

/** Create a bidirectional pipe for the given command.
*/

rwpipe *rwpipe_open( int argc, char *argv[] )
{
	rwpipe *this = av_mallocz( sizeof( rwpipe ) );

	if ( this != NULL )
	{
        int input[ 2 ];
        int output[ 2 ];

        pipe( input );
        pipe( output );

        this->pid = fork();

        if ( this->pid == 0 )
        {
			char *command = av_mallocz( 10240 );
			int i;

			strcpy( command, "" );
			for ( i = 0; i < argc; i ++ )
			{
				strcat( command, argv[ i ] );
				strcat( command, " " );
			}

            dup2( output[ 0 ], STDIN_FILENO );
            dup2( input[ 1 ], STDOUT_FILENO );

            close( input[ 0 ] );
            close( input[ 1 ] );
            close( output[ 0 ] );
            close( output[ 1 ] );

            execl("/bin/sh", "sh", "-c", command, NULL );
			exit( 255 );
        }
        else
        {
            close( input[ 1 ] );
            close( output[ 0 ] );

            this->reader = fdopen( input[ 0 ], "r" );
            this->writer = fdopen( output[ 1 ], "w" );
        }
	}

	return this;
}

/** Read data from the pipe.
*/

FILE *rwpipe_reader( rwpipe *this )
{
	if ( this != NULL )
		return this->reader;
	else
		return NULL;
}

/** Write data to the pipe.
*/

FILE *rwpipe_writer( rwpipe *this )
{
	if ( this != NULL )
		return this->writer;
	else
		return NULL;
}

/** Close the pipe and process.
*/

void rwpipe_close( rwpipe *this )
{
	if ( this != NULL )
	{
		fclose( this->reader );
		fclose( this->writer );
		waitpid( this->pid, NULL, 0 );
		av_free( this );
	}
}

typedef struct 
{
	rwpipe *rw;
} 
ContextInfo;

int Configure(void **ctxp, int argc, char *argv[])
{
    *ctxp = av_mallocz(sizeof(ContextInfo));
	if ( ctxp != NULL && argc > 1 )
	{
		ContextInfo *info = (ContextInfo *)*ctxp;
		info->rw = rwpipe_open( argc - 1, &argv[ 1 ] );
	}
    return 0;
}

int rwpipe_read_number( rwpipe *rw )
{
	int value = 0;
	int c = 0;
	FILE *in = rwpipe_reader( rw );

	do 
	{
		c = fgetc( in );

		while( c != EOF && !isdigit( c ) && c != '#' )
			c = fgetc( in );

		if ( c == '#' )
			while( c != EOF && c != '\n' )
				c = fgetc( in );
	}
	while ( c != EOF && !isdigit( c ) );

	while( c != EOF && isdigit( c ) )
	{
		value = value * 10 + ( c - '0' );
		c = fgetc( in );
	}

	return value;
}

int rwpipe_read_ppm_header( rwpipe *rw, int *width, int *height )
{
	char line[ 3 ];
	FILE *in = rwpipe_reader( rw );
	int max;

	fgets( line, 3, in );
	if ( !strncmp( line, "P6", 2 ) )
	{
		*width = rwpipe_read_number( rw );
		*height = rwpipe_read_number( rw );
		max = rwpipe_read_number( rw );
		return max != 255 || *width <= 0 || *height <= 0;
	}
	return 1;
}

void Process(void *ctx, AVPicture *picture, enum PixelFormat pix_fmt, int width, int height, int64_t pts)
{
	int err = 0;
    ContextInfo *ci = (ContextInfo *) ctx;
    char *buf1 = 0;
    char *buf2 = 0;
    AVPicture picture1;
    AVPicture picture2;
    AVPicture *pict = picture;
	int out_width;
	int out_height;
	int i;
	uint8_t *ptr = NULL;
	FILE *in = rwpipe_reader( ci->rw );
	FILE *out = rwpipe_writer( ci->rw );

	/* Convert to RGB24 if necessary */
    if (pix_fmt != PIX_FMT_RGB24) {
        int size;

        size = avpicture_get_size(PIX_FMT_RGB24, width, height);
        buf1 = av_malloc(size);

        avpicture_fill(&picture1, buf1, PIX_FMT_RGB24, width, height);
        if (img_convert(&picture1, PIX_FMT_RGB24, 
                        picture, pix_fmt, width, height) < 0) {
			err = 1;
        }
        pict = &picture1;
    }

	/* Write out the PPM */
	if ( !err )
	{
		ptr = pict->data[ 0 ];
		fprintf( out, "P6\n%d %d\n255\n", width, height );
		for ( i = 0; !err && i < height; i ++ )
		{
			err = !fwrite( ptr, width * 3, 1, out );
			ptr += pict->linesize[ 0 ];
		}
		if ( !err )
			err = fflush( out );
	}

	/* Read the PPM returned. */
	if ( !err && !rwpipe_read_ppm_header( ci->rw, &out_width, &out_height ) )
	{
        int size = avpicture_get_size(PIX_FMT_RGB24, out_width, out_height);
        buf2 = av_malloc(size);
        avpicture_fill(&picture2, buf2, PIX_FMT_RGB24, out_width, out_height);
		ptr = picture2.data[ 0 ];
		for ( i = 0; !err && i < out_height; i ++ )
		{
			err = !fread( ptr, out_width * 3, 1, in );
			ptr += picture2.linesize[ 0 ];
		}
	}

	/* Convert the returned PPM back to the input format */
	if ( !err )
	{
        if (img_convert(picture, pix_fmt, &picture2, PIX_FMT_RGB24, width, height) < 0) {
        }
	}

    av_free(buf1);
    av_free(buf2);
}

void Release(void *ctx)
{
    ContextInfo *ci;
    ci = (ContextInfo *) ctx;

    if (ctx)
	{
		rwpipe_close( ci->rw );
        av_free(ctx);
	}
}