vhook/ppm.c

   1 /*
   2  * PPM Video Hook
   3  * Copyright (c) 2003 Charles Yates
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include <stdio.h>
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include <sys/types.h>
  26 #include <sys/wait.h>
  27 #include <ctype.h>
  28 #include "libavutil/avstring.h"
  29 #include "libavformat/framehook.h"
  30 #include "libavformat/avformat.h"
  31 #include "libswscale/swscale.h"
  32 #undef fprintf
  33
  34 static int sws_flags = SWS_BICUBIC;
  35
  36 /** Bi-directional pipe structure.
  37 */
  38
  39 typedef struct rwpipe
  40 {
  41     int pid;
  42     FILE *reader;
  43     FILE *writer;
  44 }
  45 rwpipe;
  46
  47 /** Create a bidirectional pipe for the given command.
  48 */
  49
  50 static rwpipe *rwpipe_open( int argc, char *argv[] )
  51 {
  52     rwpipe *this = av_mallocz( sizeof( rwpipe ) );
  53
  54     if ( this != NULL )
  55     {
  56         int input[ 2 ];
  57         int output[ 2 ];
  58
  59         pipe( input );
  60         pipe( output );
  61
  62         this->pid = fork();
  63
  64         if ( this->pid == 0 )
  65         {
  66 #define COMMAND_SIZE 10240
  67             char *command = av_mallocz( COMMAND_SIZE );
  68             int i;
  69
  70             strcpy( command, "" );
  71             for ( i = 0; i < argc; i ++ )
  72             {
  73                 av_strlcat( command, argv[ i ], COMMAND_SIZE );
  74                 av_strlcat( command, " ", COMMAND_SIZE );
  75             }
  76
  77             dup2( output[ 0 ], STDIN_FILENO );
  78             dup2( input[ 1 ], STDOUT_FILENO );
  79
  80             close( input[ 0 ] );
  81             close( input[ 1 ] );
  82             close( output[ 0 ] );
  83             close( output[ 1 ] );
  84
  85             execl("/bin/sh", "sh", "-c", command, (char*)NULL );
  86             _exit( 255 );
  87         }
  88         else
  89         {
  90             close( input[ 1 ] );
  91             close( output[ 0 ] );
  92
  93             this->reader = fdopen( input[ 0 ], "r" );
  94             this->writer = fdopen( output[ 1 ], "w" );
  95         }
  96     }
  97
  98     return this;
  99 }
 100
 101 /** Read data from the pipe.
 102 */
 103
 104 static FILE *rwpipe_reader( rwpipe *this )
 105 {
 106     if ( this != NULL )
 107         return this->reader;
 108     else
 109         return NULL;
 110 }
 111
 112 /** Write data to the pipe.
 113 */
 114
 115 static FILE *rwpipe_writer( rwpipe *this )
 116 {
 117     if ( this != NULL )
 118         return this->writer;
 119     else
 120         return NULL;
 121 }
 122
 123 /* Read a number from the pipe - assumes PNM style headers.
 124 */
 125
 126 static int rwpipe_read_number( rwpipe *rw )
 127 {
 128     int value = 0;
 129     int c = 0;
 130     FILE *in = rwpipe_reader( rw );
 131
 132     do
 133     {
 134         c = fgetc( in );
 135
 136         while( c != EOF && !isdigit( c ) && c != '#' )
 137             c = fgetc( in );
 138
 139         if ( c == '#' )
 140             while( c != EOF && c != '\n' )
 141                 c = fgetc( in );
 142     }
 143     while ( c != EOF && !isdigit( c ) );
 144
 145     while( c != EOF && isdigit( c ) )
 146     {
 147         value = value * 10 + ( c - '0' );
 148         c = fgetc( in );
 149     }
 150
 151     return value;
 152 }
 153
 154 /** Read a PPM P6 header.
 155 */
 156
 157 static int rwpipe_read_ppm_header( rwpipe *rw, int *width, int *height )
 158 {
 159     char line[ 3 ];
 160     FILE *in = rwpipe_reader( rw );
 161     int max;
 162
 163     fgets( line, 3, in );
 164     if ( !strncmp( line, "P6", 2 ) )
 165     {
 166         *width = rwpipe_read_number( rw );
 167         *height = rwpipe_read_number( rw );
 168         max = rwpipe_read_number( rw );
 169         return max != 255 || *width <= 0 || *height <= 0;
 170     }
 171     return 1;
 172 }
 173
 174 /** Close the pipe and process.
 175 */
 176
 177 static void rwpipe_close( rwpipe *this )
 178 {
 179     if ( this != NULL )
 180     {
 181         fclose( this->reader );
 182         fclose( this->writer );
 183         waitpid( this->pid, NULL, 0 );
 184         av_free( this );
 185     }
 186 }
 187
 188 /** Context info for this vhook - stores the pipe and image buffers.
 189 */
 190
 191 typedef struct
 192 {
 193     rwpipe *rw;
 194     int size1;
 195     char *buf1;
 196     int size2;
 197     char *buf2;
 198
 199     // This vhook first converts frame to RGB ...
 200     struct SwsContext *toRGB_convert_ctx;
 201     // ... then processes it via a PPM command pipe ...
 202     // ... and finally converts back frame from RGB to initial format
 203     struct SwsContext *fromRGB_convert_ctx;
 204 }
 205 ContextInfo;
 206
 207 /** Initialise the context info for this vhook.
 208 */
 209
 210 int Configure(void **ctxp, int argc, char *argv[])
 211 {
 212     if ( argc > 1 )
 213     {
 214         *ctxp = av_mallocz(sizeof(ContextInfo));
 215         if ( *ctxp != NULL && argc > 1 )
 216         {
 217             ContextInfo *info = (ContextInfo *)*ctxp;
 218             info->rw = rwpipe_open( argc - 1, &argv[ 1 ] );
 219             return 0;
 220         }
 221     }
 222     return 1;
 223 }
 224
 225 /** Process a frame.
 226 */
 227
 228 void Process(void *ctx, AVPicture *picture, enum PixelFormat pix_fmt, int width, int height, int64_t pts)
 229 {
 230     int err = 0;
 231     ContextInfo *ci = (ContextInfo *) ctx;
 232     AVPicture picture1;
 233     AVPicture picture2;
 234     AVPicture *pict = picture;
 235     int out_width;
 236     int out_height;
 237     int i;
 238     uint8_t *ptr = NULL;
 239     FILE *in = rwpipe_reader( ci->rw );
 240     FILE *out = rwpipe_writer( ci->rw );
 241
 242     /* Check that we have a pipe to talk to. */
 243     if ( in == NULL || out == NULL )
 244         err = 1;
 245
 246     /* Convert to RGB24 if necessary */
 247     if ( !err && pix_fmt != PIX_FMT_RGB24 )
 248     {
 249         int size = avpicture_get_size(PIX_FMT_RGB24, width, height);
 250
 251         if ( size != ci->size1 )
 252         {
 253             av_free( ci->buf1 );
 254             ci->buf1 = av_malloc(size);
 255             ci->size1 = size;
 256             err = ci->buf1 == NULL;
 257         }
 258
 259         if ( !err )
 260         {
 261             avpicture_fill(&picture1, ci->buf1, PIX_FMT_RGB24, width, height);
 262
 263             // if we already got a SWS context, let's realloc if is not re-useable
 264             ci->toRGB_convert_ctx = sws_getCachedContext(ci->toRGB_convert_ctx,
 265                                         width, height, pix_fmt,
 266                                         width, height, PIX_FMT_RGB24,
 267                                         sws_flags, NULL, NULL, NULL);
 268             if (ci->toRGB_convert_ctx == NULL) {
 269                 av_log(NULL, AV_LOG_ERROR,
 270                        "Cannot initialize the toRGB conversion context\n");
 271                 return;
 272             }
 273
 274 // img_convert parameters are          2 first destination, then 4 source
 275 // sws_scale   parameters are context, 4 first source,      then 2 destination
 276             sws_scale(ci->toRGB_convert_ctx,
 277                      picture->data, picture->linesize, 0, height,
 278                      picture1.data, picture1.linesize);
 279
 280             pict = &picture1;
 281         }
 282     }
 283
 284     /* Write out the PPM */
 285     if ( !err )
 286     {
 287         ptr = pict->data[ 0 ];
 288         fprintf( out, "P6\n%d %d\n255\n", width, height );
 289         for ( i = 0; !err && i < height; i ++ )
 290         {
 291             err = !fwrite( ptr, width * 3, 1, out );
 292             ptr += pict->linesize[ 0 ];
 293         }
 294         if ( !err )
 295             err = fflush( out );
 296     }
 297
 298     /* Read the PPM returned. */
 299     if ( !err && !rwpipe_read_ppm_header( ci->rw, &out_width, &out_height ) )
 300     {
 301         int size = avpicture_get_size(PIX_FMT_RGB24, out_width, out_height);
 302
 303         if ( size != ci->size2 )
 304         {
 305             av_free( ci->buf2 );
 306             ci->buf2 = av_malloc(size);
 307             ci->size2 = size;
 308             err = ci->buf2 == NULL;
 309         }
 310
 311         if ( !err )
 312         {
 313             avpicture_fill(&picture2, ci->buf2, PIX_FMT_RGB24, out_width, out_height);
 314             ptr = picture2.data[ 0 ];
 315             for ( i = 0; !err && i < out_height; i ++ )
 316             {
 317                 err = !fread( ptr, out_width * 3, 1, in );
 318                 ptr += picture2.linesize[ 0 ];
 319             }
 320         }
 321     }
 322
 323     /* Convert the returned PPM back to the input format */
 324     if ( !err )
 325     {
 326         /* The out_width/out_height returned from the PPM
 327          * filter won't necessarily be the same as width and height
 328          * but it will be scaled anyway to width/height.
 329          */
 330         av_log(NULL, AV_LOG_DEBUG,
 331                   "PPM vhook: Input dimensions: %d x %d Output dimensions: %d x %d\n",
 332                   width, height, out_width, out_height);
 333         ci->fromRGB_convert_ctx = sws_getCachedContext(ci->fromRGB_convert_ctx,
 334                                         out_width, out_height, PIX_FMT_RGB24,
 335                                         width,     height,     pix_fmt,
 336                                         sws_flags, NULL, NULL, NULL);
 337         if (ci->fromRGB_convert_ctx == NULL) {
 338             av_log(NULL, AV_LOG_ERROR,
 339                    "Cannot initialize the fromRGB conversion context\n");
 340             return;
 341         }
 342
 343 // img_convert parameters are          2 first destination, then 4 source
 344 // sws_scale   parameters are context, 4 first source,      then 2 destination
 345         sws_scale(ci->fromRGB_convert_ctx,
 346                  picture2.data, picture2.linesize, 0, out_height,
 347                  picture->data, picture->linesize);
 348     }
 349 }
 350
 351 /** Clean up the effect.
 352 */
 353
 354 void Release(void *ctx)
 355 {
 356     ContextInfo *ci;
 357     ci = (ContextInfo *) ctx;
 358
 359     if (ctx)
 360     {
 361         rwpipe_close( ci->rw );
 362         av_free( ci->buf1 );
 363         av_free( ci->buf2 );
 364         sws_freeContext(ci->toRGB_convert_ctx);
 365         sws_freeContext(ci->fromRGB_convert_ctx);
 366         av_free(ctx);
 367     }
 368 }
 369