rockbox/apps/buffering.h
Nicolas Pennequin 9d4bed7ff0 Album art support. Based on FS#3045, but heavily modified to adapt to MoB and for cleanness.
The cover pictures are loaded from external bitmaps. JPEG and embedded art are not supported. The pictures will only be drawn on the main display. There is no resizing but it is possible to specify the WPS bitmap size in the bitmap names (e.g. cover.100x100.bmp).
The bitmaps are stored in the main buffer and read directly from there. Currently, duplicate bitmaps will simply be present several times in the buffer, but this will be improved.
To enable for a target, #define HAVE_ALBUMART in its config file.
For more information, see the wiki page: http://www.rockbox.org/wiki/AlbumArt.


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15572 a1c6a512-1295-4272-9138-f99709370657
2007-11-11 12:29:37 +00:00

133 lines
4.4 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2007 Nicolas Pennequin
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#ifndef _BUFFERING_H_
#define _BUFFERING_H_
#include <sys/types.h>
#include <stdbool.h>
enum data_type {
TYPE_CODEC,
TYPE_PACKET_AUDIO,
TYPE_ATOMIC_AUDIO,
TYPE_ID3,
TYPE_CUESHEET,
TYPE_BITMAP,
TYPE_BUFFER,
TYPE_UNKNOWN,
};
/* Error return values */
#define ERR_HANDLE_NOT_FOUND -1
#define ERR_BUFFER_FULL -2
#define ERR_INVALID_VALUE -3
#define ERR_FILE_ERROR -4
/* Initialise the buffering subsystem */
void buffering_init(void);
/* Reset the buffering system */
bool buffering_reset(char *buf, size_t buflen);
/***************************************************************************
* MAIN BUFFERING API CALLS
* ========================
*
* bufopen : Reserve space in the buffer for a given file
* bufalloc : Open a new handle from data that needs to be copied from memory
* bufclose : Close an open handle
* bufseek : Set handle reading index, relatively to the start of the file
* bufadvance: Move handle reading index, relatively to current position
* bufread : Copy data from a handle to a buffer
* bufgetdata: Obtain a pointer for linear access to a "size" amount of data
*
* NOTE: bufread and bufgetdata will block the caller until the requested
* amount of data is ready (unless EOF is reached).
****************************************************************************/
#define BUF_MAX_HANDLES 256
int bufopen(const char *file, size_t offset, enum data_type type);
int bufalloc(const void *src, size_t size, enum data_type type);
bool bufclose(int handle_id);
int bufseek(int handle_id, size_t newpos);
int bufadvance(int handle_id, off_t offset);
ssize_t bufread(int handle_id, size_t size, void *dest);
ssize_t bufgetdata(int handle_id, size_t size, void **data);
/***************************************************************************
* SECONDARY FUNCTIONS
* ===================
*
* buf_get_offset: Get a handle offset from a pointer
* buf_handle_offset: Get the offset of the first buffered byte from the file
* buf_request_buffer_handle: Request buffering of a handle
* buf_set_base_handle: Tell the buffering thread which handle is currently read
* buf_used: Total amount of buffer space used (including allocated space)
****************************************************************************/
ssize_t buf_get_offset(int handle_id, void *ptr);
ssize_t buf_handle_offset(int handle_id);
void buf_request_buffer_handle(int handle_id);
void buf_set_base_handle(int handle_id);
size_t buf_used(void);
/***************************************************************************
* CALLBACK UTILITIES
* ==================
*
* register_buffer_low_callback, unregister_buffer_low_callback:
*
* Register/Unregister callback functions that will get executed when the buffer
* goes below the low watermark. They are executed once, then forgotten.
*
* NOTE: The callbacks are called from the buffering thread, so don't make them
* do too much. Ideally they should just post an event to a queue and return.
****************************************************************************/
#define MAX_BUF_CALLBACKS 4
typedef void (*buffer_low_callback)(void);
bool register_buffer_low_callback(buffer_low_callback func);
void unregister_buffer_low_callback(buffer_low_callback func);
/* Settings */
enum {
BUFFERING_SET_WATERMARK = 1,
BUFFERING_SET_CHUNKSIZE,
};
void buf_set_watermark(size_t bytes);
/* Debugging */
struct buffering_debug {
int num_handles;
size_t buffered_data;
size_t wasted_space;
size_t data_rem;
size_t useful_data;
};
void buffering_get_debugdata(struct buffering_debug *dbgdata);
#endif