[Cin] UPD: Writing 16-bit per component png?

Andrew Randrianasulu randrianasulu at gmail.com
Tue Mar 17 06:47:40 CET 2020


В сообщении от Tuesday 17 March 2020 04:57:28 Phyllis Smith написал(а):
> Hey Andrew:
> If you get a stable patch, GG would very much like to have it !!  THANKS,
> Phyllis/gg

Attached patch works for me - autoswitches between 8 and 16 bit per channel depending on project settings.
Thing is, I'm not sure if best_colormodel can be bumped to RGB(a)161616 ? I mean, this is 
correct for preserving color info, but isn't it also double memory requrements for ALL pngs loaded?

Or for this native_cmodel is used,

> 
> On Mon, Mar 16, 2020 at 1:56 PM Andrew Randrianasulu <
> randrianasulu at gmail.com> wrote:
> 
> >
> > Oh, I was setting functions in wrong order:
> >
> >
> > int FilePNG::write_frame(VFrame *frame, VFrame *data, FrameWriterUnit
> > *unit)
> > {
> >         PNGUnit *png_unit = (PNGUnit*)unit;
> >         png_structp png_ptr = 0;
> >         png_infop info_ptr = 0;
> >         VFrame *output_frame;
> >         int result = 1;
> >         int is_float = (frame->get_color_model() == BC_RGBA_FLOAT ||
> > frame->get_color_model() == BC_RGB_FLOAT);
> >
> >         data->set_compressed_size(0);
> > //printf("FilePNG::write_frame 1\n");
> >         native_cmodel = asset->png_use_alpha ? BC_RGBA8888 : BC_RGB888;
> >         if (is_float)
> >         native_cmodel = asset->png_use_alpha ? BC_RGBA16161616 :
> > BC_RGB161616;
> >
> >         if(frame->get_color_model() != native_cmodel)
> >         {
> >                 if(!png_unit->temp_frame) png_unit->temp_frame =
> >                         new VFrame(asset->width, asset->height,
> > native_cmodel, 0);
> >
> >                 png_unit->temp_frame->transfer_from(frame);
> >                 output_frame = png_unit->temp_frame;
> >         }
> >         else
> >                 output_frame = frame;
> >
> > //printf("FilePNG::write_frame 1\n");
> >         png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
> >         if( png_ptr ) {
> >                 if( !setjmp(png_jmpbuf(png_ptr)) ) {
> >                         info_ptr = png_create_info_struct(png_ptr);
> >                         png_set_write_fn(png_ptr, data,
> >                                 (png_rw_ptr)write_function,
> > (png_flush_ptr)flush_function);
> >                         png_set_compression_level(png_ptr,
> > asset->png_compression);
> >
> >                         png_set_IHDR(png_ptr, info_ptr, asset->width,
> > asset->height, is_float ? 16 : 8,
> >                                 asset->png_use_alpha ?
> > PNG_COLOR_TYPE_RGB_ALPHA : PNG_COLOR_TYPE_RGB,
> >                                 PNG_INTERLACE_NONE,
> > PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
> >                         png_write_info(png_ptr, info_ptr);
> >                         if(is_float)
> >                         png_set_swap(png_ptr); <======
> >                         png_write_image(png_ptr, output_frame->get_rows());
> >                         png_write_end(png_ptr, info_ptr);
> >                         result = 0;
> >                 }
> >                 png_destroy_write_struct(&png_ptr, &info_ptr);
> >         }
> >         if( result ) {
> >                 char error[256];  png_error(png_ptr, error);
> >                 fprintf(stderr, "FilePNG::write_frame failed: %s\n",
> > error);
> >         }
> > //printf("FilePNG::write_frame 3 %d\n", data->get_compressed_size());
> >         return result;
> > }
> >
> > hint found via
> >
> > https://github.com/GNOME/gimp/blob/mainline/plug-ins/common/file-png.c
> >
> > png_set_swap  must come AFTER png_write_info!
> >
> >
> >
> > ----------  Пересланное сообщение  ----------
> >
> > Тема: Writing 16-bit per component png?
> > Дата: Понедельник 16 марта 2020
> > Отправитель: Andrew Randrianasulu <randrianasulu at gmail.com>
> > Получатель:  "Cinelerra.GG" <cin at lists.cinelerra-gg.org>
> >
> > Probably stupid misuse of libpng api on my side ...
> >
> > I tried to add support for writing 16 bit per component PNGs into Cin.
> >
> > int FilePNG::write_frame(VFrame *frame, VFrame *data, FrameWriterUnit
> > *unit)
> > {
> >  PNGUnit *png_unit = (PNGUnit*)unit;
> >  png_structp png_ptr = 0;
> >  png_infop info_ptr = 0;
> >  VFrame *output_frame;
> >  int result = 1;
> >  int is_float = (frame->get_color_model() == BC_RGBA_FLOAT ||
> > frame->get_color_model() == BC_RGB_FLOAT);
> >
> > ==== here I try to get idea if project's colormodel actually *-FLOAT or
> > not ====
> >
> >  data->set_compressed_size(0);
> > //printf("FilePNG::write_frame 1\n");
> >  native_cmodel = asset->png_use_alpha ? BC_RGBA8888 : BC_RGB888;
> >  if (is_float)
> >  native_cmodel = asset->png_use_alpha ? BC_RGBA16161616 : BC_RGB161616;
> >
> > === here I try to set native_colormodel to wide-channel integer format, if
> > input was FP ====
> >
> >  if(frame->get_color_model() != native_cmodel)
> >  {
> >   if(!png_unit->temp_frame) png_unit->temp_frame =
> >    new VFrame(asset->width, asset->height, native_cmodel, 0);
> >
> >   png_unit->temp_frame->transfer_from(frame);
> >   output_frame = png_unit->temp_frame;
> >  }
> >  else
> >   output_frame = frame;
> >
> > //printf("FilePNG::write_frame 1\n");
> >  png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
> >  if( png_ptr ) {
> >   if( !setjmp(png_jmpbuf(png_ptr)) ) {
> >    info_ptr = png_create_info_struct(png_ptr);
> >    png_set_write_fn(png_ptr, data,
> >     (png_rw_ptr)write_function, (png_flush_ptr)flush_function);
> >    png_set_compression_level(png_ptr, asset->png_compression);
> >
> >    png_set_IHDR(png_ptr, info_ptr, asset->width, asset->height, is_float ?
> > 16 : 8,
> >     asset->png_use_alpha ?  PNG_COLOR_TYPE_RGB_ALPHA : PNG_COLOR_TYPE_RGB,
> >     PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
> > PNG_FILTER_TYPE_DEFAULT);
> >
> > ==== here I try to call libpng with different bit depth depending on
> > is_float ======
> >
> >    png_write_info(png_ptr, info_ptr);
> >    png_write_image(png_ptr, output_frame->get_rows());
> >    png_write_end(png_ptr, info_ptr);
> >    result = 0;
> >   }
> >   png_destroy_write_struct(&png_ptr, &info_ptr);
> >  }
> >  if( result ) {
> >   char error[256];  png_error(png_ptr, error);
> >   fprintf(stderr, "FilePNG::write_frame failed: %s\n", error);
> >  }
> > //printf("FilePNG::write_frame 3 %d\n", data->get_compressed_size());
> >  return result;
> > }
> >
> > I also modified
> >
> >
> > int FilePNG::get_best_colormodel(Asset *asset, int driver)
> > {
> >  if(asset->png_use_alpha)
> >   //return BC_RGBA8888;
> >   return BC_RGBA16161616;
> >  else
> >   //return BC_RGB888;
> >   return BC_RGB161616;
> > }
> >
> > but probably those changes alone not enough, I get wrong colors or
> > completely transparent picture in resulted png ?
> >
> > -------------------------------------------------------
> > --
> > Cin mailing list
> > Cin at lists.cinelerra-gg.org
> > https://lists.cinelerra-gg.org/mailman/listinfo/cin
> >
> 


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