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• Is it possibel extract thumbnails and save them on website using youtube video. (by front-end users)

  24 octobre 2013, par Jaewook Koh

  I read blog about print youtube video on "http://www.labnol.org/internet/print-youtube-video/28217/".

  I have a self-hosted video site.

  But video hosting makes too many traffic.

  So I decideed another plan for site.

  It's to generate thumbnails of external video. Is it possible?

  I found making thumbnails using ffmpeg, but there are a lot of videos in external platform(Like Youtube, Vimeo, etc)

  After I saw Amit Agarwal's blog("print youtube video"), I was very impressed.

  Anyway if it is impossible, I should find another way.

  Thanks-

• How to access Nested structure member variables

  24 octobre 2013, par JAYANTHI

  I have an structure

  typedef struct AVFilter {
  
      const char *name;
      const char *description;
      const AVFilterPad *inputs;
      const AVFilterPad *outputs;
      const AVClass *priv_class;
      int flags;
      int (*init)(AVFilterContext *ctx);
      int (*init_dict)(AVFilterContext *ctx, AVDictionary **options);
      void (*uninit)(AVFilterContext *ctx);
      int (*query_formats)(AVFilterContext *);
      int priv_size;      
      struct AVFilter *next;
      int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags);
      int (*init_opaque)(AVFilterContext *ctx, void *opaque);
  
  } AVFilter;
  

  I dont knw how to access nested structure variables and my code is,

      AVFilter avfilter_vsrc_color = {
      avfilter_vsrc_color.name            = "color",
      avfilter_vsrc_color.description     = NULL_IF_CONFIG_SMALL("Provide an uniformly colored input."),
      avfilter_vsrc_color.priv_class      = &color_class, // error here
      avfilter_vsrc_color.priv_size       = sizeof(TestSourceContext),
      avfilter_vsrc_color.init            = color_init,
      avfilter_vsrc_color.uninit          = uninit,
      avfilter_vsrc_color.query_formats   = color_query_formats,
      avfilter_vsrc_color.inputs          = NULL,
      avfilter_vsrc_color.outputs         = color_outputs,
      avfilter_vsrc_color.process_command = color_process_command
  };
  

  I have compiled the code in vs2010 and I m Getting error like

  c:\users\awki6\desktop\ffmpeg\libavfilter\vsrc_testsrc.cpp(273): error C2440: 'initializing' : cannot convert from 'const AVClass *' to 'const AVFilterPad *'
  2>          Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast
  

• ACCESSING STRUCTURE VARIABLES

  24 octobre 2013, par JAYANTHI

  I have an structure AVFilter,

  AVFilter avfilter_vsrc_color = {  
      .name            = "color",  // error here
      .description     = NULL_IF_CONFIG_SMALL("Provide an uniformly colored input."),  
      .priv_class      = &color_class,  
      .priv_size       = sizeof(TestSourceContext),  
      .init            = color_init,  
      .uninit          = uninit,  
      .query_formats   = color_query_formats,  
      .inputs          = NULL,  
      .outputs         = color_outputs,  
      .process_command = color_process_command,  
  };
  

  and AVFilter is defined as,

  typedef struct AVFilter {
  
      const char *name;
      const char *description;
      const AVFilterPad *inputs;
      const AVFilterPad *outputs;
      const AVClass *priv_class;
      int flags;
      int (*init)(AVFilterContext *ctx);
      int (*init_dict)(AVFilterContext *ctx, AVDictionary **options);
      void (*uninit)(AVFilterContext *ctx);
      int (*query_formats)(AVFilterContext *);
      int priv_size;      ///< size of private data to allocate for the filter
      struct AVFilter *next;
      int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags);
      int (*init_opaque)(AVFilterContext *ctx, void *opaque);
  
  } AVFilter;
  

  I m getting error like ,

  2>c:\users\awki6\desktop\ffmpeg\libavfilter\vsrc_testsrc.cpp(268): error C2143: syntax error : missing '}' before '.'  
  2>c:\users\awki6\desktop\ffmpeg\libavfilter\vsrc_testsrc.cpp(268): error C2143: syntax error : missing ';' before '.'  
  2>c:\users\awki6\desktop\ffmpeg\libavfilter\vsrc_testsrc.cpp(268): error C2059: syntax error : '.'
  

• Syntax error : missing '{ ' before '.'

  24 octobre 2013, par JAYANTHI

  I have an AVOption structure:

  static const AVOption options[] = {  
          COMMON_OPTIONS  // error here
          { NULL }  
      };
  

  and COMMON_OPTIONS is defined as:

  #define COMMON_OPTIONS \
  { "interp", "select interpolation mode", OFFSET(interpolation), AV_OPT_TYPE_INT, {.i64=INTERPOLATE_TETRAHEDRAL}, 0, NB_INTERP_MODE-1, FLAGS, "interp_mode" }, \
  {NULL}
  

  I am getting an error:

  2>c:\users\awki6\desktop\ffmpeg\libavfilter\vsrc_testsrc.cpp(98): error C2143: syntax error : missing '}' before '.'
  

• Missing ; before return

  24 octobre 2013, par JAYANTHI

  This is my piece of code, I'm compiling in VS2010:

  static inline int ff_insert_inpad(AVFilterContext *f, unsigned index, AVFilterPad *p)  
      {  
          int ret = ff_insert_pad(index, &f->nb_inputs, offsetof(AVFilterLink, dstpad), &f->input_pads, &f->inputs, p); 
  
      #if FF_API_FOO_COUNT
      FF_DISABLE_DEPRECATION_WARNINGS  
          f->input_count = f->nb_inputs;  
      FF_ENABLE_DEPRECATION_WARNINGS        
      #endif
  
          return ret; // error here
  
  
      }
  

  I'm getting errors like:

  2>c:\users\awki6\desktop\ffmpeg\libavfilter\internal.h(271): error C2143: syntax error : missing ';' before 'return'