/*
* PPM Video Hook
* Copyright (c) 2003 Charles Yates
*
* 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 <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <ctype.h>
#include "libavutil/avstring.h"
#include "libavformat/framehook.h"
#include "libavformat/avformat.h"
#include "libswscale/swscale.h"
#undef fprintf
static int sws_flags = SWS_BICUBIC;
/** Bi-directional pipe structure.
*/
typedef struct rwpipe
{
int pid;
FILE *reader;
FILE *writer;
}
rwpipe;
/** Create a bidirectional pipe for the given command.
*/
static rwpipe *rwpipe_open( int argc, char *argv[] )
{
rwpipe *this = av_mallocz( sizeof( rwpipe ) );
if ( this != NULL )
{
int input[ 2 ];
int output[ 2 ];
if (!pipe( input ))
return NULL;
if (!pipe( output ))
return NULL;
this->pid = fork();
if ( this->pid == 0 )
{
#define COMMAND_SIZE 10240
char *command = av_mallocz( COMMAND_SIZE );
int i;
strcpy( command, "" );
for ( i = 0; i < argc; i ++ )
{
av_strlcat( command, argv[ i ], COMMAND_SIZE );
av_strlcat( command, " ", COMMAND_SIZE );
}
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, (char*)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.
*/
static FILE *rwpipe_reader( rwpipe *this )
{
if ( this != NULL )
return this->reader;
else
return NULL;
}
/** Write data to the pipe.
*/
static FILE *rwpipe_writer( rwpipe *this )
{
if ( this != NULL )
return this->writer;
else
return NULL;
}
/* Read a number from the pipe - assumes PNM style headers.
*/
static 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;
}
/** Read a PPM P6 header.
*/
static int rwpipe_read_ppm_header( rwpipe *rw, int *width, int *height )
{
char line[ 3 ];
FILE *in = rwpipe_reader( rw );
int max;
if (!fgets( line, 3, in ))
return -1;
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;
}
/** Close the pipe and process.
*/
static void rwpipe_close( rwpipe *this )
{
if ( this != NULL )
{
fclose( this->reader );
fclose( this->writer );
waitpid( this->pid, NULL, 0 );
av_free( this );
}
}
/** Context info for this vhook - stores the pipe and image buffers.
*/
typedef struct
{
rwpipe *rw;
int size1;
char *buf1;
int size2;
char *buf2;
// This vhook first converts frame to RGB ...
struct SwsContext *toRGB_convert_ctx;
// ... then processes it via a PPM command pipe ...
// ... and finally converts back frame from RGB to initial format
struct SwsContext *fromRGB_convert_ctx;
}
ContextInfo;
/** Initialise the context info for this vhook.
*/
int Configure(void **ctxp, int argc, char *argv[])
{
if ( argc > 1 )
{
*ctxp = av_mallocz(sizeof(ContextInfo));
if ( *ctxp != NULL && argc > 1 )
{
ContextInfo *info = (ContextInfo *)*ctxp;
info->rw = rwpipe_open( argc - 1, &argv[ 1 ] );
return 0;
}
}
return 1;
}
/** Process a frame.
*/
void Process(void *ctx, AVPicture *picture, enum PixelFormat pix_fmt, int width, int height, int64_t pts)
{
int err = 0;
ContextInfo *ci = (ContextInfo *) ctx;
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 );
/* Check that we have a pipe to talk to. */
if ( in == NULL || out == NULL )
err = 1;
/* Convert to RGB24 if necessary */
if ( !err && pix_fmt != PIX_FMT_RGB24 )
{
int size = avpicture_get_size(PIX_FMT_RGB24, width, height);
if ( size != ci->size1 )
{
av_free( ci->buf1 );
ci->buf1 = av_malloc(size);
ci->size1 = size;
err = ci->buf1 == NULL;
}
if ( !err )
{
avpicture_fill(&picture1, ci->buf1, PIX_FMT_RGB24, width, height);
// if we already got a SWS context, let's realloc if is not re-useable
ci->toRGB_convert_ctx = sws_getCachedContext(ci->toRGB_convert_ctx,
width, height, pix_fmt,
width, height, PIX_FMT_RGB24,
sws_flags, NULL, NULL, NULL);
if (ci->toRGB_convert_ctx == NULL) {
av_log(NULL, AV_LOG_ERROR,
"Cannot initialize the toRGB conversion context\n");
return;
}
// img_convert parameters are 2 first destination, then 4 source
// sws_scale parameters are context, 4 first source, then 2 destination
sws_scale(ci->toRGB_convert_ctx,
picture->data, picture->linesize, 0, height,
picture1.data, picture1.linesize);
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);
if ( size != ci->size2 )
{
av_free( ci->buf2 );
ci->buf2 = av_malloc(size);
ci->size2 = size;
err = ci->buf2 == NULL;
}
if ( !err )
{
avpicture_fill(&picture2, ci->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 )
{
/* The out_width/out_height returned from the PPM
* filter won't necessarily be the same as width and height
* but it will be scaled anyway to width/height.
*/
av_log(NULL, AV_LOG_DEBUG,
"PPM vhook: Input dimensions: %d x %d Output dimensions: %d x %d\n",
width, height, out_width, out_height);
ci->fromRGB_convert_ctx = sws_getCachedContext(ci->fromRGB_convert_ctx,
out_width, out_height, PIX_FMT_RGB24,
width, height, pix_fmt,
sws_flags, NULL, NULL, NULL);
if (ci->fromRGB_convert_ctx == NULL) {
av_log(NULL, AV_LOG_ERROR,
"Cannot initialize the fromRGB conversion context\n");
return;
}
// img_convert parameters are 2 first destination, then 4 source
// sws_scale parameters are context, 4 first source, then 2 destination
sws_scale(ci->fromRGB_convert_ctx,
picture2.data, picture2.linesize, 0, out_height,
picture->data, picture->linesize);
}
}
/** Clean up the effect.
*/
void Release(void *ctx)
{
ContextInfo *ci;
ci = (ContextInfo *) ctx;
if (ctx)
{
rwpipe_close( ci->rw );
av_free( ci->buf1 );
av_free( ci->buf2 );
sws_freeContext(ci->toRGB_convert_ctx);
sws_freeContext(ci->fromRGB_convert_ctx);
av_free(ctx);
}
}