/* * 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"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 ];        pipe( input );        pipe( output );        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;    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;}/** 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);    }}