92 lines
2.3 KiB
C
92 lines
2.3 KiB
C
/*
|
|
** USB_rle.h
|
|
**
|
|
** Copyright 1999, Be Incorporated. All Rights Reserved.
|
|
**
|
|
*/
|
|
|
|
#ifndef _USB_RLE_H
|
|
#define _USB_RLE_H
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
struct _usbd_param_hdr;
|
|
|
|
/*
|
|
Run Length encoding records for isochronous IN transfers.
|
|
|
|
Run Length encoding records are used to identify which samples in
|
|
the buffer are good which are bad and which are missing.
|
|
Bad bytes are not extracted from the buffer, but are padded to next
|
|
nearest sample boundary. The ultimate consumer of the buffer
|
|
should also receive the RLE array.
|
|
|
|
RLE records are constructed based on the following rules:
|
|
|
|
1. an RLE record contains a sample count and a status
|
|
(good, bad, missing or unknown). A buffer has
|
|
associated with it an array of rle records. The number of
|
|
rle records available is specified in the RLE header. The
|
|
number used is also in the RLE header.
|
|
|
|
2. Within the scope of a buffer, successive packets with the
|
|
same completion status are represented with (1) rle record.
|
|
For example, after three transactions which have completion
|
|
status of success, the byte count in the rle record for this
|
|
position in the data stream represents the bytes received in
|
|
all three packets.
|
|
|
|
3. New rle records are initialized each time the status for a
|
|
given packet differs from that of the previous packet.
|
|
|
|
*/
|
|
|
|
#define RLE_GOOD 1
|
|
#define RLE_BAD 2
|
|
#define RLE_MISSING 3
|
|
#define RLE_UNKNOWN 4
|
|
|
|
/*
|
|
Name: rle
|
|
Purpose: used to represent the state of a portion of a data buffer
|
|
Fields:
|
|
rle_status will contain only the values: RLE_GOOD, RLE_BAD, RLE_MISSING
|
|
sample_count the number of usb samples in the buffer associated with this rle
|
|
record.
|
|
Notes:
|
|
If the buffer length field in queue_buffer_single structure changes to an
|
|
uint32 from uin16, then the sample_count data type must
|
|
track this change.
|
|
*/
|
|
typedef struct rle {
|
|
uint16 rle_status;
|
|
uint16 sample_count;
|
|
} rle;
|
|
|
|
|
|
/*
|
|
Name: rlea
|
|
Purpose: used as the primary rle information data structure between the
|
|
USB driver stack and a consuming client.
|
|
|
|
Fields:
|
|
length the number of rle records available in this structure.
|
|
num_valid filled in by the USB driver. indicates the number of valid
|
|
records filled.
|
|
rles[] unconstrained array of rle records.
|
|
*/
|
|
typedef struct rlea {
|
|
uint16 length;
|
|
uint16 num_valid;
|
|
rle rles[1];
|
|
} rlea;
|
|
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif
|