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vhook/ppm.c

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00001 /*
00002  * PPM Video Hook
00003  * Copyright (c) 2003 Charles Yates
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include <stdio.h>
00023 #include <unistd.h>
00024 #include <fcntl.h>
00025 #include <sys/types.h>
00026 #include <sys/wait.h>
00027 #include <ctype.h>
00028 #include "libavutil/avstring.h"
00029 #include "libavformat/framehook.h"
00030 #include "libavformat/avformat.h"
00031 #include "libswscale/swscale.h"
00032 #undef fprintf
00033 
00034 static int sws_flags = SWS_BICUBIC;
00035 
00039 typedef struct rwpipe
00040 {
00041     int pid;
00042     FILE *reader;
00043     FILE *writer;
00044 }
00045 rwpipe;
00046 
00050 static rwpipe *rwpipe_open( int argc, char *argv[] )
00051 {
00052     rwpipe *this = av_mallocz( sizeof( rwpipe ) );
00053 
00054     if ( this != NULL )
00055     {
00056         int input[ 2 ];
00057         int output[ 2 ];
00058 
00059         if (!pipe( input ))
00060             return NULL;
00061 
00062         if (!pipe( output ))
00063             return NULL;
00064 
00065         this->pid = fork();
00066 
00067         if ( this->pid == 0 )
00068         {
00069 #define COMMAND_SIZE 10240
00070             char *command = av_mallocz( COMMAND_SIZE );
00071             int i;
00072 
00073             strcpy( command, "" );
00074             for ( i = 0; i < argc; i ++ )
00075             {
00076                 av_strlcat( command, argv[ i ], COMMAND_SIZE );
00077                 av_strlcat( command, " ", COMMAND_SIZE );
00078             }
00079 
00080             dup2( output[ 0 ], STDIN_FILENO );
00081             dup2( input[ 1 ], STDOUT_FILENO );
00082 
00083             close( input[ 0 ] );
00084             close( input[ 1 ] );
00085             close( output[ 0 ] );
00086             close( output[ 1 ] );
00087 
00088             execl("/bin/sh", "sh", "-c", command, (char*)NULL );
00089             _exit( 255 );
00090         }
00091         else
00092         {
00093             close( input[ 1 ] );
00094             close( output[ 0 ] );
00095 
00096             this->reader = fdopen( input[ 0 ], "r" );
00097             this->writer = fdopen( output[ 1 ], "w" );
00098         }
00099     }
00100 
00101     return this;
00102 }
00103 
00107 static FILE *rwpipe_reader( rwpipe *this )
00108 {
00109     if ( this != NULL )
00110         return this->reader;
00111     else
00112         return NULL;
00113 }
00114 
00118 static FILE *rwpipe_writer( rwpipe *this )
00119 {
00120     if ( this != NULL )
00121         return this->writer;
00122     else
00123         return NULL;
00124 }
00125 
00126 /* Read a number from the pipe - assumes PNM style headers.
00127 */
00128 
00129 static int rwpipe_read_number( rwpipe *rw )
00130 {
00131     int value = 0;
00132     int c = 0;
00133     FILE *in = rwpipe_reader( rw );
00134 
00135     do
00136     {
00137         c = fgetc( in );
00138 
00139         while( c != EOF && !isdigit( c ) && c != '#' )
00140             c = fgetc( in );
00141 
00142         if ( c == '#' )
00143             while( c != EOF && c != '\n' )
00144                 c = fgetc( in );
00145     }
00146     while ( c != EOF && !isdigit( c ) );
00147 
00148     while( c != EOF && isdigit( c ) )
00149     {
00150         value = value * 10 + ( c - '0' );
00151         c = fgetc( in );
00152     }
00153 
00154     return value;
00155 }
00156 
00160 static int rwpipe_read_ppm_header( rwpipe *rw, int *width, int *height )
00161 {
00162     char line[ 3 ];
00163     FILE *in = rwpipe_reader( rw );
00164     int max;
00165 
00166     if (!fgets( line, 3, in ))
00167         return -1;
00168 
00169     if ( !strncmp( line, "P6", 2 ) )
00170     {
00171         *width = rwpipe_read_number( rw );
00172         *height = rwpipe_read_number( rw );
00173         max = rwpipe_read_number( rw );
00174         return max != 255 || *width <= 0 || *height <= 0;
00175     }
00176     return 1;
00177 }
00178 
00182 static void rwpipe_close( rwpipe *this )
00183 {
00184     if ( this != NULL )
00185     {
00186         fclose( this->reader );
00187         fclose( this->writer );
00188         waitpid( this->pid, NULL, 0 );
00189         av_free( this );
00190     }
00191 }
00192 
00196 typedef struct
00197 {
00198     rwpipe *rw;
00199     int size1;
00200     char *buf1;
00201     int size2;
00202     char *buf2;
00203 
00204     // This vhook first converts frame to RGB ...
00205     struct SwsContext *toRGB_convert_ctx;
00206     // ... then processes it via a PPM command pipe ...
00207     // ... and finally converts back frame from RGB to initial format
00208     struct SwsContext *fromRGB_convert_ctx;
00209 }
00210 ContextInfo;
00211 
00215 int Configure(void **ctxp, int argc, char *argv[])
00216 {
00217     if ( argc > 1 )
00218     {
00219         *ctxp = av_mallocz(sizeof(ContextInfo));
00220         if ( *ctxp != NULL && argc > 1 )
00221         {
00222             ContextInfo *info = (ContextInfo *)*ctxp;
00223             info->rw = rwpipe_open( argc - 1, &argv[ 1 ] );
00224             return 0;
00225         }
00226     }
00227     return 1;
00228 }
00229 
00233 void Process(void *ctx, AVPicture *picture, enum PixelFormat pix_fmt, int width, int height, int64_t pts)
00234 {
00235     int err = 0;
00236     ContextInfo *ci = (ContextInfo *) ctx;
00237     AVPicture picture1;
00238     AVPicture picture2;
00239     AVPicture *pict = picture;
00240     int out_width;
00241     int out_height;
00242     int i;
00243     uint8_t *ptr = NULL;
00244     FILE *in = rwpipe_reader( ci->rw );
00245     FILE *out = rwpipe_writer( ci->rw );
00246 
00247     /* Check that we have a pipe to talk to. */
00248     if ( in == NULL || out == NULL )
00249         err = 1;
00250 
00251     /* Convert to RGB24 if necessary */
00252     if ( !err && pix_fmt != PIX_FMT_RGB24 )
00253     {
00254         int size = avpicture_get_size(PIX_FMT_RGB24, width, height);
00255 
00256         if ( size != ci->size1 )
00257         {
00258             av_free( ci->buf1 );
00259             ci->buf1 = av_malloc(size);
00260             ci->size1 = size;
00261             err = ci->buf1 == NULL;
00262         }
00263 
00264         if ( !err )
00265         {
00266             avpicture_fill(&picture1, ci->buf1, PIX_FMT_RGB24, width, height);
00267 
00268             // if we already got a SWS context, let's realloc if is not re-useable
00269             ci->toRGB_convert_ctx = sws_getCachedContext(ci->toRGB_convert_ctx,
00270                                         width, height, pix_fmt,
00271                                         width, height, PIX_FMT_RGB24,
00272                                         sws_flags, NULL, NULL, NULL);
00273             if (ci->toRGB_convert_ctx == NULL) {
00274                 av_log(NULL, AV_LOG_ERROR,
00275                        "Cannot initialize the toRGB conversion context\n");
00276                 return;
00277             }
00278 
00279 // img_convert parameters are          2 first destination, then 4 source
00280 // sws_scale   parameters are context, 4 first source,      then 2 destination
00281             sws_scale(ci->toRGB_convert_ctx,
00282                      picture->data, picture->linesize, 0, height,
00283                      picture1.data, picture1.linesize);
00284 
00285             pict = &picture1;
00286         }
00287     }
00288 
00289     /* Write out the PPM */
00290     if ( !err )
00291     {
00292         ptr = pict->data[ 0 ];
00293         fprintf( out, "P6\n%d %d\n255\n", width, height );
00294         for ( i = 0; !err && i < height; i ++ )
00295         {
00296             err = !fwrite( ptr, width * 3, 1, out );
00297             ptr += pict->linesize[ 0 ];
00298         }
00299         if ( !err )
00300             err = fflush( out );
00301     }
00302 
00303     /* Read the PPM returned. */
00304     if ( !err && !rwpipe_read_ppm_header( ci->rw, &out_width, &out_height ) )
00305     {
00306         int size = avpicture_get_size(PIX_FMT_RGB24, out_width, out_height);
00307 
00308         if ( size != ci->size2 )
00309         {
00310             av_free( ci->buf2 );
00311             ci->buf2 = av_malloc(size);
00312             ci->size2 = size;
00313             err = ci->buf2 == NULL;
00314         }
00315 
00316         if ( !err )
00317         {
00318             avpicture_fill(&picture2, ci->buf2, PIX_FMT_RGB24, out_width, out_height);
00319             ptr = picture2.data[ 0 ];
00320             for ( i = 0; !err && i < out_height; i ++ )
00321             {
00322                 err = !fread( ptr, out_width * 3, 1, in );
00323                 ptr += picture2.linesize[ 0 ];
00324             }
00325         }
00326     }
00327 
00328     /* Convert the returned PPM back to the input format */
00329     if ( !err )
00330     {
00331         /* The out_width/out_height returned from the PPM
00332          * filter won't necessarily be the same as width and height
00333          * but it will be scaled anyway to width/height.
00334          */
00335         av_log(NULL, AV_LOG_DEBUG,
00336                   "PPM vhook: Input dimensions: %d x %d Output dimensions: %d x %d\n",
00337                   width, height, out_width, out_height);
00338         ci->fromRGB_convert_ctx = sws_getCachedContext(ci->fromRGB_convert_ctx,
00339                                         out_width, out_height, PIX_FMT_RGB24,
00340                                         width,     height,     pix_fmt,
00341                                         sws_flags, NULL, NULL, NULL);
00342         if (ci->fromRGB_convert_ctx == NULL) {
00343             av_log(NULL, AV_LOG_ERROR,
00344                    "Cannot initialize the fromRGB conversion context\n");
00345             return;
00346         }
00347 
00348 // img_convert parameters are          2 first destination, then 4 source
00349 // sws_scale   parameters are context, 4 first source,      then 2 destination
00350         sws_scale(ci->fromRGB_convert_ctx,
00351                  picture2.data, picture2.linesize, 0, out_height,
00352                  picture->data, picture->linesize);
00353     }
00354 }
00355 
00359 void Release(void *ctx)
00360 {
00361     ContextInfo *ci;
00362     ci = (ContextInfo *) ctx;
00363 
00364     if (ctx)
00365     {
00366         rwpipe_close( ci->rw );
00367         av_free( ci->buf1 );
00368         av_free( ci->buf2 );
00369         sws_freeContext(ci->toRGB_convert_ctx);
00370         sws_freeContext(ci->fromRGB_convert_ctx);
00371         av_free(ctx);
00372     }
00373 }
00374 

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