1 TODO file: 2 ---------- 3 4 COMPATIBILITY fixes: 5 6 1. COMPATIBILITY: dual-mode devices, i.e. devices exposing both an MTP 7 and a USB Mass Storage Device Class (flashdrive) interface are and 8 have always been problematic. We must find a way to get this to work, 9 eventually. The problem is that the in-kernel mass storage driver hogs 10 the device before the MTP mode gets a chance of being used, whereas 11 the Windows kernel driver apparently does it the other way around, 12 trying the MTP mode first and then not fall back on mass storage if 13 MTP is available. (For some more explanations se src/libusb-glue.h.) 14 This may involve kernel modifications. Perhaps it is only necessary 15 to tweak the udev config not to load USB mass storage support for 16 these devices. Dunno. 17 18 2. COMPATIBILITY: several devices tend to "hang" after disconnect, 19 needing to be unplugged and replugged before they can be used again. 20 We don't know why, it may be related to low-level USB behaviour that 21 is not exposed in the logs we read. On some devices it appear that 22 avoiding to release the USB interface after closing the PTP/MTP 23 session solves this, and might be a hint at how the Windows MTP stack 24 works: perhaps the Windows MTP daemon grabs the interface once the 25 device is plugged in, created a session and NEVER release it. 26 Thus only unplug or shutdown ends the session. This behaviour can be 27 emulated (sort of) by DEVICE_FLAG_NO_RELEASE_INTERFACE which will 28 make the device not release the USB low-level interface, though it'll 29 still close the session. But is it really desireable to have 30 as default? Not unless we run an MTP daemon as well, probably, and 31 the behaviour is questionable from an USB interoperability point 32 of view. 33 34 35 SPEEDUP fixes: 36 37 None known. libmtp is fast :-) 38 39 40 FEATURE fixes: 41 42 1. FEATURE: Support playback and volume setting on devices that have it. 43 (I don't have one that does - Linus.) 44 45 2. FEATURE: Support relevant events. MTP devices seen in existance provide 46 events for "object added" and "object deleted". These should result in 47 atleast a call to the cache update function. 48 49 3. FEATURE: Mechanism to retrieve the device icon device property, else if not 50 present, look for DevIcon.fil (Windows ICO format) and 51 DevLogo.fil (PNG Format) images from the device (if available). 52 53 4. FEATURE: Shared device access so that multiple client applications can have 54 an open connection to the device at the same time via a handle. For example, 55 it should be somehow possible to run mtp-detect at the same time as amarok or 56 mtpfs is connected to a device. This would require some form of resource 57 sharing. 58 59 5. FEATURE: Implement an OpenSync backend for devices which have 60 calendaring, contact etc support. http://opensync.org/ 61 62 63 THOSE ARE ALREADY DONE: 64 65 1. FEATURE: Make an API that can return several devices and let the user 66 choose which one to operate, not just connect to the first one... 67 68 2. SPEED: Cache the object info for all items on the device. 69 Right now, ptp_getobjectinfo() is called repeatedly on the same 70 objects during startup, track listing, file listing, playlist listing, 71 album listing and whatever we implement tomorrow. A lot of useless 72 communication can be saved by cacheing this info. Notice that this 73 needs to be updated whenever flush_handles() is called too. 74 (This came from libgphoto2 implementing it!) 75 76 3. SPEED: Cache track metadata, file metadata etc in params->proplist. 77 78 4. SPEED: Whenever we add an object (file, track, playlist...) we 79 should only need to update the cache with relevant data. Atleast for 80 speedup caches. 81 82 5. COMPATIBILITY: account for different step sizes and intervals on some 83 numeric properties we set, make the functions round off when possible. 84 85 6. SPEED: Cache the supported object properties at first read/startup. 86 then use the cache to check for supported props instead of calling 87 out to PTP with ptp_mtp_getobjectpropssupported() every time. 88 The cache would be an array of size params->deviceinfo.ImageFormats_len 89 with a list for each format of the properties it will support. Notice 90 that this needs to be updated whenever flush_handles() is called too. 91 THIS HAS BEEN DISCARDED, TERO IMPLEMENTED IT BUT IT DOESN'T SEEM TO 92 YIELD MUCH. 93 94 7. FEATURE: Make abstract playlists really become size -1 when created as 95 the ones created on the device instead of the current 1 byte size. 96 (Is this possible using enhanced commands? See TODO remarks in 97 the create_abstract_entity() function) 98 99 8. FEATURE: Integrate libmtp with HAL / D-Bus so applications can dynamically 100 know when a device has been plugged in or removed. Need a mechanism to 101 connect a specific hal UDI. 102 103 9. SPEEDUP: The recursive function that builds the folder tree is 104 O(n^2)! Atleast remove all non-folders (PTP associations) from the 105 list before we start sorting and building that tree. We walk the 106 entire list for each group of siblings right now! 107
