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libusb: use alternate setting 1 for now, add table for iso packet size for each alt setting

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This commit is contained in:
Matthias Ringwald 2017-01-19 12:12:25 +01:00
parent a11bf4163d
commit f34d119bfa
1 changed files with 13 additions and 3 deletions
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16
platform/libusb/hci_transport_h2_libusb.c
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@ -85,13 +85,23 @@
// 4: Two 8 kHz voice channels with 16-bit encoding or one 16 kHz voice channel with 16-bit encoding
// 5: Three 8 kHz voice channels with 16-bit encoding or one 8 kHz voice channel with 16-bit encoding and one 16 kHz voice channel with 16-bit encoding
// --> support only a single SCO connection
#define ALT_SETTING (2)
#define ALT_SETTING (1)
// for ALT_SETTING >= 1 and 8-bit channel, we need the following isochronous packets
// One complete SCO packet with 24 frames every 3 frames (== 3 ms)
#define NUM_ISO_PACKETS (3)
// results in 9 bytes per frame
#define ISO_PACKET_SIZE (9)
const uint16_t iso_packet_size_for_alt_setting[] = {
0,
9,
17,
25,
33,
49,
63,
};
#define ISO_PACKET_SIZE (iso_packet_size_for_alt_setting[ALT_SETTING])
// 49 bytes is the max usb packet size for alternate setting 5 (Three 8 kHz 16-bit channels or one 8 kHz 16-bit channel and one 16 kHz 16-bit channel)
// note: alt setting 6 has max packet size of 63 every 7.5 ms = 472.5 bytes / HCI packet, while max SCO packet has 255 byte payload