t4_tx.h File Reference

Go to the source code of this file.

Typedefs

typedef int(* t4_row_read_handler_t )(void *user_data, uint8_t buf[], size_t len)
typedef struct t4_tx_state_s t4_tx_state_t

Functions

t4_tx_state_t * t4_tx_init (t4_tx_state_t *s, const char *file, int start_page, int stop_page)
 Prepare for transmission of a document.
int t4_tx_start_page (t4_tx_state_t *s)
 Prepare to send the next page of the current document.
int t4_tx_restart_page (t4_tx_state_t *s)
 Prepare the current page for a resend.
int t4_tx_next_page_has_different_format (t4_tx_state_t *s)
 Check for the existance of the next page, and whether its format is like the current one. This information can be needed before it is determined that the current page is finished with.
int t4_tx_end_page (t4_tx_state_t *s)
 Complete the sending of a page.
int t4_tx_image_complete (t4_tx_state_t *s)
 Return the next bit of the current document page, without actually moving forward in the buffer. The document will be padded for the current minimum scan line time.
int t4_tx_get_bit (t4_tx_state_t *s)
 Get the next bit of the current document page. The document will be padded for the current minimum scan line time.
int t4_tx_get (t4_tx_state_t *s, uint8_t buf[], size_t max_len)
 Get the next chunk of the current document page. The document will be padded for the current minimum scan line time.
int t4_tx_release (t4_tx_state_t *s)
 End the transmission of a document. Tidy up and close the file. This should be used to end T.4 transmission started with t4_tx_init.
int t4_tx_free (t4_tx_state_t *s)
 End the transmission of a document. Tidy up, close the file and free the context. This should be used to end T.4 transmission started with t4_tx_init.
int t4_tx_set_tx_encoding (t4_tx_state_t *s, int encoding)
 Set the encoding for the encoded data.
void t4_tx_set_min_bits_per_row (t4_tx_state_t *s, int bits)
 Set the minimum number of encoded bits per row. This allows the makes the encoding process to be set to comply with the minimum row time specified by a remote receiving machine.
void t4_tx_set_image_width (t4_tx_state_t *s, int image_width)
 Set the width of the image.
void t4_tx_set_max_2d_rows_per_1d_row (t4_tx_state_t *s, int max)
 Set the maximum number of 2D encoded rows between 1D encoded rows. This is only valid for T.4 2D encoding.
void t4_tx_set_local_ident (t4_tx_state_t *s, const char *ident)
 Set the identity of the local machine, for inclusion in page headers.
void t4_tx_set_header_info (t4_tx_state_t *s, const char *info)
 Set the header info.
void t4_tx_set_header_tz (t4_tx_state_t *s, tz_t *tz)
 Set the header timezone.
void t4_tx_set_header_overlays_image (t4_tx_state_t *s, int header_overlays_image)
 Set page header overlay mode.
int t4_tx_set_row_read_handler (t4_tx_state_t *s, t4_row_read_handler_t handler, void *user_data)
 Set the row read handler for a T.4 transmit context.
void t4_tx_set_row_squashing_ratio (t4_tx_state_t *s, int row_squashing_ratio)
 Set the row squashing ratio, for adjusting row-to-row (y) resolution of bi-level images for a T.4 transmit context.
int t4_tx_get_y_resolution (t4_tx_state_t *s)
 Get the row-to-row (y) resolution of the current page.
int t4_tx_get_x_resolution (t4_tx_state_t *s)
 Get the column-to-column (x) resolution of the current page.
int t4_tx_get_image_width (t4_tx_state_t *s)
 Get the width of the current page, in pixel columns.
int t4_tx_get_pages_in_file (t4_tx_state_t *s)
 Get the number of pages in the file.
int t4_tx_get_current_page_in_file (t4_tx_state_t *s)
 Get the currnet page number in the file.
void t4_tx_get_transfer_statistics (t4_tx_state_t *s, t4_stats_t *t)
 Get the current transfer statistics.

Detailed Description

Typedef Documentation

typedef int(* t4_row_read_handler_t)(void *user_data, uint8_t buf[], size_t len)

This function is a callback from the image decoders, to read the unencoded bi-level image, row by row. It is called for each row, with len set to the number of bytes per row expected.

Returns:
len for OK, or zero to indicate the end of the image data.
typedef struct t4_tx_state_s t4_tx_state_t

T.4 FAX compression/decompression descriptor. This defines the working state for a single instance of a T.4 FAX compression or decompression channel.

Function Documentation

int t4_tx_end_page ( t4_tx_state_t *  s  ) 

Complete the sending of a page.

Parameters:
s The T.4 context.
Returns:
zero for success, -1 for failure.
int t4_tx_free ( t4_tx_state_t *  s  ) 

End the transmission of a document. Tidy up, close the file and free the context. This should be used to end T.4 transmission started with t4_tx_init.

Parameters:
s The T.4 context.
Returns:
0 for success, otherwise -1.

References t4_tx_release().

int t4_tx_get ( t4_tx_state_t *  s,
uint8_t  buf[],
size_t  max_len 
)

Get the next chunk of the current document page. The document will be padded for the current minimum scan line time.

Parameters:
s The T.4 context.
buf The buffer into which the chunk is to written.
max_len The maximum length of the chunk.
Returns:
The actual length of the chunk. If this is less than max_len it indicates that the end of the document has been reached.

References T4_COMPRESSION_ITU_T42, T4_COMPRESSION_ITU_T43, T4_COMPRESSION_ITU_T4_1D, T4_COMPRESSION_ITU_T4_2D, T4_COMPRESSION_ITU_T6, T4_COMPRESSION_ITU_T85, T4_COMPRESSION_ITU_T85_L0, t4_t6_encode_get(), and t85_encode_get().

Referenced by t30_non_ecm_get().

int t4_tx_get_bit ( t4_tx_state_t *  s  ) 

Get the next bit of the current document page. The document will be padded for the current minimum scan line time.

Parameters:
s The T.4 context.
Returns:
The next bit (i.e. 0 or 1). SIG_STATUS_END_OF_DATA for no more data.

References t4_t6_encode_get_bit().

Referenced by SPAN_DECLARE_NONSTD().

int t4_tx_get_current_page_in_file ( t4_tx_state_t *  s  ) 

Get the currnet page number in the file.

Parameters:
s The T.4 context.
Returns:
The page number, or -1 if there is an error.
int t4_tx_get_image_width ( t4_tx_state_t *  s  ) 

Get the width of the current page, in pixel columns.

Parameters:
s The T.4 context.
Returns:
The number of columns.
int t4_tx_get_pages_in_file ( t4_tx_state_t *  s  ) 

Get the number of pages in the file.

Parameters:
s The T.4 context.
Returns:
The number of pages, or -1 if there is an error.
void t4_tx_get_transfer_statistics ( t4_tx_state_t *  s,
t4_stats_t *  t 
)

Get the current transfer statistics.

Get the current image transfer statistics.

Parameters:
s The T.4 context.
t A pointer to a statistics structure.

References T4_COMPRESSION_ITU_T42, T4_COMPRESSION_ITU_T43, T4_COMPRESSION_ITU_T4_1D, T4_COMPRESSION_ITU_T4_2D, T4_COMPRESSION_ITU_T6, T4_COMPRESSION_ITU_T85, T4_COMPRESSION_ITU_T85_L0, t4_t6_encode_get_compressed_image_size(), t4_t6_encode_get_image_length(), t4_t6_encode_get_image_width(), t85_encode_get_compressed_image_size(), t85_encode_get_image_length(), and t85_encode_get_image_width().

Referenced by t30_get_transfer_statistics().

int t4_tx_get_x_resolution ( t4_tx_state_t *  s  ) 

Get the column-to-column (x) resolution of the current page.

Parameters:
s The T.4 context.
Returns:
The resolution, in pixels per metre.
int t4_tx_get_y_resolution ( t4_tx_state_t *  s  ) 

Get the row-to-row (y) resolution of the current page.

Parameters:
s The T.4 context.
Returns:
The resolution, in pixels per metre.
int t4_tx_image_complete ( t4_tx_state_t *  s  ) 

Return the next bit of the current document page, without actually moving forward in the buffer. The document will be padded for the current minimum scan line time.

Parameters:
s The T.4 context.
Returns:
0 for more data to come. SIG_STATUS_END_OF_DATA for no more data.

References SIG_STATUS_END_OF_DATA, t42_encode_image_complete(), T4_COMPRESSION_ITU_T42, T4_COMPRESSION_ITU_T43, T4_COMPRESSION_ITU_T4_1D, T4_COMPRESSION_ITU_T4_2D, T4_COMPRESSION_ITU_T6, T4_COMPRESSION_ITU_T85, T4_COMPRESSION_ITU_T85_L0, t4_t6_encode_image_complete(), and t85_encode_image_complete().

t4_tx_state_t* t4_tx_init ( t4_tx_state_t *  s,
const char *  file,
int  start_page,
int  stop_page 
)

Prepare for transmission of a document.

Parameters:
s The T.4 context.
file The name of the file to be sent.
start_page The first page to send. -1 for no restriction.
stop_page The last page to send. -1 for no restriction.
Returns:
A pointer to the context, or NULL if there was a problem.

References span_log(), and T4_COMPRESSION_NONE.

int t4_tx_next_page_has_different_format ( t4_tx_state_t *  s  ) 

Check for the existance of the next page, and whether its format is like the current one. This information can be needed before it is determined that the current page is finished with.

Parameters:
s The T.4 context.
Returns:
0 for next page found with the same format as the current page. 1 for next page found with different format from the current page. -1 for no page found, or file failure.

References span_log().

int t4_tx_release ( t4_tx_state_t *  s  ) 

End the transmission of a document. Tidy up and close the file. This should be used to end T.4 transmission started with t4_tx_init.

Parameters:
s The T.4 context.
Returns:
0 for success, otherwise -1.

References T4_COMPRESSION_ITU_T42, T4_COMPRESSION_ITU_T43, T4_COMPRESSION_ITU_T4_1D, T4_COMPRESSION_ITU_T4_2D, T4_COMPRESSION_ITU_T6, T4_COMPRESSION_ITU_T85, and T4_COMPRESSION_ITU_T85_L0.

Referenced by t4_tx_free().

int t4_tx_restart_page ( t4_tx_state_t *  s  ) 

Prepare the current page for a resend.

Parameters:
s The T.4 context.
Returns:
zero for success, -1 for failure.

References t4_tx_start_page().

void t4_tx_set_header_info ( t4_tx_state_t *  s,
const char *  info 
)

Set the header info.

Set the info field, included in the header line included in each page of an encoded FAX. This is a string of up to 50 characters. Other information (date, local ident, etc.) are automatically included in the header. If the header info is set to NULL or a zero length string, no header lines will be added to the encoded FAX.

Parameters:
s The T.4 context.
info A string, of up to 50 bytes, which will form the info field.

Referenced by t30_set_tx_page_header_info().

void t4_tx_set_header_overlays_image ( t4_tx_state_t *  s,
int  header_overlays_image 
)

Set page header overlay mode.

Set page header extends or overlays the image mode.

Parameters:
s The T.4 context.
header_overlays_image TRUE for overlay, or FALSE for extend the page.

Referenced by t30_set_tx_page_header_overlays_image().

void t4_tx_set_header_tz ( t4_tx_state_t *  s,
tz_t *  tz 
)

Set the header timezone.

Set the time zone for the time stamp in page header lines. If this function is not used the current time zone of the program's environment is used.

Parameters:
s The T.4 context.
tz A time zone descriptor.

Referenced by t30_set_tx_page_header_tz().

void t4_tx_set_image_width ( t4_tx_state_t *  s,
int  image_width 
)

Set the width of the image.

Parameters:
s The T.4 context.
image_width The image width, in pixels.

References T4_COMPRESSION_ITU_T42, T4_COMPRESSION_ITU_T43, T4_COMPRESSION_ITU_T4_1D, T4_COMPRESSION_ITU_T4_2D, T4_COMPRESSION_ITU_T6, T4_COMPRESSION_ITU_T85, T4_COMPRESSION_ITU_T85_L0, t4_t6_encode_set_image_width(), and t85_encode_set_image_width().

void t4_tx_set_local_ident ( t4_tx_state_t *  s,
const char *  ident 
)

Set the identity of the local machine, for inclusion in page headers.

Parameters:
s The T.4 context.
ident The identity string.

Referenced by t30_set_tx_ident().

void t4_tx_set_max_2d_rows_per_1d_row ( t4_tx_state_t *  s,
int  max 
)

Set the maximum number of 2D encoded rows between 1D encoded rows. This is only valid for T.4 2D encoding.

Parameters:
s The T.4 context.
max The maximum number of 2D rows.

References T4_COMPRESSION_ITU_T4_1D, T4_COMPRESSION_ITU_T4_2D, T4_COMPRESSION_ITU_T6, and t4_t6_encode_set_max_2d_rows_per_1d_row().

void t4_tx_set_min_bits_per_row ( t4_tx_state_t *  s,
int  bits 
)

Set the minimum number of encoded bits per row. This allows the makes the encoding process to be set to comply with the minimum row time specified by a remote receiving machine.

Parameters:
s The T.4 context.
bits The minimum number of bits per row.

References T4_COMPRESSION_ITU_T4_1D, T4_COMPRESSION_ITU_T4_2D, T4_COMPRESSION_ITU_T6, and t4_t6_encode_set_min_bits_per_row().

int t4_tx_set_row_read_handler ( t4_tx_state_t *  s,
t4_row_read_handler_t  handler,
void *  user_data 
)

Set the row read handler for a T.4 transmit context.

Parameters:
s The T.4 transmit context.
handler A pointer to the handler routine.
user_data An opaque pointer passed to the handler routine.
Returns:
0 for success, otherwise -1.
void t4_tx_set_row_squashing_ratio ( t4_tx_state_t *  s,
int  row_squashing_ratio 
)

Set the row squashing ratio, for adjusting row-to-row (y) resolution of bi-level images for a T.4 transmit context.

Parameters:
s The T.4 transmit context.
row_squashing_ratio Vertical squashing ratio.
int t4_tx_set_tx_encoding ( t4_tx_state_t *  s,
int  encoding 
)

Set the encoding for the encoded data.

Parameters:
s The T.4 context.
encoding The encoding.
Returns:
0 for success, otherwise -1.

References T4_COMPRESSION_ITU_T42, T4_COMPRESSION_ITU_T43, T4_COMPRESSION_ITU_T4_1D, T4_COMPRESSION_ITU_T4_2D, T4_COMPRESSION_ITU_T6, T4_COMPRESSION_ITU_T85, T4_COMPRESSION_ITU_T85_L0, t4_t6_encode_init(), t4_t6_encode_set_encoding(), t4_t6_encode_set_max_2d_rows_per_1d_row(), and t85_encode_init().

int t4_tx_start_page ( t4_tx_state_t *  s  ) 

Prepare to send the next page of the current document.

Parameters:
s The T.4 context.
Returns:
zero for success, -1 for failure.

References span_log(), T4_COMPRESSION_ITU_T42, T4_COMPRESSION_ITU_T43, T4_COMPRESSION_ITU_T4_1D, T4_COMPRESSION_ITU_T4_2D, T4_COMPRESSION_ITU_T6, T4_COMPRESSION_ITU_T85, T4_COMPRESSION_ITU_T85_L0, t4_encoding_to_str(), t4_t6_encode_restart(), and t85_encode_restart().

Referenced by t4_tx_restart_page().

Generated on 15 Sep 2012 for spandsp by  doxygen 1.6.1