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