Commit 858f38cf authored by Tristan Matthews's avatar Tristan Matthews
Browse files

png: add encoder

parent 453264d4
......@@ -33,12 +33,31 @@
#include <vlc_codec.h>
#include <png.h>
/* PNG_SYS_COMMON_MEMBERS:
* members common to encoder and decoder descriptors
*/
#define PNG_SYS_COMMON_MEMBERS \
/**@{*/ \
bool b_error; \
vlc_object_t *p_obj; \
/**@}*/ \
/*
* png common descriptor
*/
struct png_sys_t
{
PNG_SYS_COMMON_MEMBERS
};
typedef struct png_sys_t png_sys_t;
/*****************************************************************************
* decoder_sys_t : png decoder descriptor
*****************************************************************************/
struct decoder_sys_t
{
bool b_error;
PNG_SYS_COMMON_MEMBERS
};
/*****************************************************************************
......@@ -49,6 +68,20 @@ static void CloseDecoder ( vlc_object_t * );
static picture_t *DecodeBlock ( decoder_t *, block_t ** );
/*
* png encoder descriptor
*/
struct encoder_sys_t
{
PNG_SYS_COMMON_MEMBERS
int i_blocksize;
};
static int OpenEncoder(vlc_object_t *);
static void CloseEncoder(vlc_object_t *);
static block_t *EncodeBlock(encoder_t *, picture_t *);
/*****************************************************************************
* Module descriptor
*****************************************************************************/
......@@ -59,6 +92,14 @@ vlc_module_begin ()
set_capability( "decoder", 1000 )
set_callbacks( OpenDecoder, CloseDecoder )
add_shortcut( "png" )
/* encoder submodule */
add_submodule()
add_shortcut("png")
set_section(N_("Encoding"), NULL)
set_description(N_("PNG video encoder"))
set_capability("encoder", 1000)
set_callbacks(OpenEncoder, CloseEncoder)
vlc_module_end ()
/*****************************************************************************
......@@ -78,6 +119,8 @@ static int OpenDecoder( vlc_object_t *p_this )
if( ( p_dec->p_sys = malloc(sizeof(decoder_sys_t)) ) == NULL )
return VLC_ENOMEM;
p_dec->p_sys->p_obj = p_this;
/* Set output properties */
p_dec->fmt_out.i_cat = VIDEO_ES;
p_dec->fmt_out.i_codec = VLC_CODEC_RGBA;
......@@ -101,17 +144,40 @@ static void user_read( png_structp p_png, png_bytep data, png_size_t i_length )
p_block->i_buffer -= i_length;
}
static void user_flush( png_structp p_png )
{
/* noop */
(void) p_png;
}
static void user_write( png_structp p_png, png_bytep data, png_size_t i_length )
{
block_t *p_block = (block_t *)png_get_io_ptr( p_png );
if( i_length > p_block->i_buffer ) {
char err_str[64];
snprintf( err_str, sizeof(err_str),
"block size %zu too small for %zu encoded bytes",
p_block->i_buffer, i_length );
png_error( p_png, err_str );
return;
}
memcpy( p_block->p_buffer, data, i_length );
p_block->p_buffer += i_length;
p_block->i_buffer -= i_length;
}
static void user_error( png_structp p_png, png_const_charp error_msg )
{
decoder_t *p_dec = (decoder_t *)png_get_error_ptr( p_png );
p_dec->p_sys->b_error = true;
msg_Err( p_dec, "%s", error_msg );
png_sys_t *p_sys = (png_sys_t *)png_get_error_ptr( p_png );
p_sys->b_error = true;
msg_Err( p_sys->p_obj, "%s", error_msg );
}
static void user_warning( png_structp p_png, png_const_charp warning_msg )
{
decoder_t *p_dec = (decoder_t *)png_get_error_ptr( p_png );
msg_Warn( p_dec, "%s", warning_msg );
png_sys_t *p_sys = (png_sys_t *)png_get_error_ptr( p_png );
msg_Warn( p_sys->p_obj, "%s", warning_msg );
}
/****************************************************************************
......@@ -253,3 +319,125 @@ static void CloseDecoder( vlc_object_t *p_this )
free( p_sys );
}
static int OpenEncoder(vlc_object_t *p_this)
{
encoder_t *p_enc = (encoder_t *) p_this;
if( p_enc->fmt_out.i_codec != VLC_CODEC_PNG )
return VLC_EGENERIC;
/* Allocate the memory needed to store the encoder's structure */
p_enc->p_sys = malloc( sizeof(encoder_sys_t) );
if( p_enc->p_sys == NULL )
return VLC_ENOMEM;
p_enc->p_sys->p_obj = p_this;
p_enc->p_sys->i_blocksize = 3 * p_enc->fmt_in.video.i_visible_width *
p_enc->fmt_in.video.i_visible_height;
p_enc->fmt_in.i_codec = VLC_CODEC_RGB24;
p_enc->fmt_in.video.i_rmask = 0x000000ff;
p_enc->fmt_in.video.i_gmask = 0x0000ff00;
p_enc->fmt_in.video.i_bmask = 0x00ff0000;
p_enc->pf_encode_video = EncodeBlock;
return VLC_SUCCESS;
}
/*
* EncodeBlock
*/
static block_t *EncodeBlock(encoder_t *p_enc, picture_t *p_pic)
{
encoder_sys_t *p_sys = p_enc->p_sys;
if( unlikely( !p_pic ) )
{
return NULL;
}
block_t *p_block = block_Alloc( p_sys->i_blocksize );
if( p_block == NULL )
{
return NULL;
}
png_structp p_png = png_create_write_struct( PNG_LIBPNG_VER_STRING, 0, 0, 0 );
if( p_png == NULL )
{
block_Release( p_block );
return NULL;
}
/* save buffer start */
uint8_t *p_start = p_block->p_buffer;
size_t i_start = p_block->i_buffer;
p_sys->b_error = false;
png_infop p_info = NULL;
/* libpng longjmp's there in case of error */
if( setjmp( png_jmpbuf( p_png ) ) )
goto error;
png_set_write_fn( p_png, p_block, user_write, user_flush );
png_set_error_fn( p_png, p_enc, user_error, user_warning );
p_info = png_create_info_struct( p_png );
if( p_info == NULL )
goto error;
png_infop p_end_info = png_create_info_struct( p_png );
if( p_end_info == NULL ) goto error;
const unsigned i_width = p_enc->fmt_in.video.i_visible_width;
const unsigned i_height = p_enc->fmt_in.video.i_visible_height;
png_set_IHDR( p_png, p_info,
i_width,
i_height,
8, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT );
if( p_sys->b_error ) goto error;
png_write_info( p_png, p_info );
if( p_sys->b_error ) goto error;
/* Encode picture */
for( unsigned i = 0; i < i_height; i++ )
{
png_write_row( p_png, p_pic->p->p_pixels + (i_width * i * 3));
if( p_sys->b_error ) goto error;
}
png_write_end( p_png, p_end_info );
if( p_sys->b_error ) goto error;
png_destroy_write_struct( &p_png, &p_info );
/* restore original buffer position */
p_block->p_buffer = p_start;
p_block->i_buffer = i_start;
return p_block;
error:
png_destroy_write_struct( &p_png, p_info ? &p_info : NULL );
block_Release(p_block);
return NULL;
}
/*****************************************************************************
* CloseEncoder: png encoder destruction
*****************************************************************************/
static void CloseEncoder( vlc_object_t *p_this )
{
encoder_t *p_enc = (encoder_t *)p_this;
encoder_sys_t *p_sys = p_enc->p_sys;
free( p_sys );
}
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