Hands-On Workshop: Freescale Audio Solution Framework, Part 2

Transcription

1 Hands-On Workshop: Freescale Audio Solution Framework, Part 2 FTF-SDS-F0131 Justin Lydick Software Architect Jason Martin Software Manager A P R External Use

2 Agenda Introduction of FAS Framework (recap from part 1) Major Software Components and APIs FAS Configuration and Build Overview Build Requirements Source Organization Configuration Program Hands-On Applications FAS comprehensive test application test_app Audio Device Detection and Enumeration Audio Device Browse and Playback External Use 1

3 Freescale Audio Solution Introduction Recap Components and Base APIs External Use 2

4 Freescale Audio Solution: OSA Operating System Abstraction (OSA) Write code once for any OS / platform Bridge the gap between POSIX and non-posix OSes Functional today on MQX, Linux, and some components on bare metal Key APIs Create and schedule tasks / threads Synchronization: mutexes, semaphores, events Messaging Dynamic memory allocation File and directory operations Time and date External Use 3

5 Freescale Audio Solution: Common Libraries Common Libraries Utility libraries, data types, and algorithms for platform use Key APIs Container data types: list, vector, and iterators Logging platform Module setup and enable / disable Level setup (debug, warning, info, error) and enable / disable Destination setup (console, file, memory) String utilities Unicode / UTF-8 <string.h> extensions like strlcpy() External Use 4

6 Freescale Audio Solution: Platform APIs Device Manager Runs as a separate task Manages external devices: USB/SD, Apple, Android, CD, BT, etc Key APIs devicemgr_get_all_device_list() devicemgr_msg_queue_register() External Use 5

7 Freescale Audio Solution: Platform APIs Input Manager Runs as a separate task Manages various types of application inputs: buttons, knobs (quadrature), touch, CAN / network, and input simulation Optional mapping of inputs to platform behaviors: previous / next track, play / pause, volume up / down, etc. Key APIs inputmgr_get_current_device_info() inputmgr_msg_queue_register() External Use 6

8 Freescale Audio Solution: Platform APIs Maestro Audio Framework Largest component of the FAS platform Handles playback and media library browsing of media data from a variety of sources and types Streamer-based handling of input and output sources, as well as media codecs allows easy extensibility for new types Also allows filters to be written for audio data processing Key Components Media Device Abstraction (MediaDev) Browser Player Play Queue Streamer Tuner External Use 7

9 Freescale Audio Solution: Platform APIs Application interacts with Maestro using several components Player Object Playback control of audio from connected device Tuner Object AM/FM tuner playback control Play Queue Object Manages a list of audio tracks on a filesystem device Controls shuffle and repeat modes Browse Object Browse files or entities on a connected device Media Device Object Abstracts externally controlled devices (Apple, Bluetooth, CD, etc) Streamer Reads data from devices, parses and decodes it, and passes output to appropriate output device Creates a pipeline of elements that are built dynamically based on input and output devices as well as the type of data to be processed Abstracted using Streamer Abstraction Layer (SAL) to allow replacement with third-party streamers like gstreamer on Linux External Use 8

10 Freescale Audio Solution: Platform APIs Maestro Media Device mediadev_create() Maestro Browser browse_create() browse_enter_folder() / browse_exit_folder() browse_get_entries() Accepts limits and offset parameters Uses browse session context to determine location browse_get_track_info() / browse_get_album_art() External Use 9

11 Freescale Audio Solution: Platform APIs Maestro Player player_create() player_set_track() player_control() Stop, Play, Pause, Next, Previous, Fast Forward, Rewind, and others External Use 10

12 Freescale Audio Solution Configuration and Build External Use 11

13 Platform Build Requirements Linux or Windows host environment Currently requiring 32-bit Ubuntu (server or desktop) >= Cygwin under Windows also works GCC cross-compiler for ARM target Building successfully with ARM, Mentor, and Linaro GCC cross-compiler can generate Linux or MQX libraries and apps Libc Should come with the compiler Using GNU libc on Linux and newlib with MQX GNU binutils and make External Use 12

14 Debugging and Boot Options Lauterbach with Trace32 Preferred debugging method Other JTAG solution GDB using Segger SD card boot U-boot bootloader can boot an application image on card or tftp-boot remote image (useful for rapid development and debugging) External Use 13

15 Release Package Source Organization mydir ----fsl_fas ->source code fas ->software platform infrastructure ->build infrastructure tools ->flash programmer image scripts ->debugger & configuration tool os ->OS kernel and device drivers apps ->sample applications ----doc ->documentation ----bootloader ->bootloader (U-Boot) ----build ->pre-built default image External Use 14

16 Infrastructure Top-level repository used for building and configuring the platform Build infrastructure all done using GNU make Flexible: can work using command-line or integrated into GUI tools like Eclipse Makefile supports the following targets: (no args): build all repositories and generate test_app command-line media player build : same as no arguments target to build platform config : starts fasconfig configuration program clean : removes all object files, libs, and binaries across the platform configclean : wipe out user-created configuration and restore to default External Use 15

17 Configuration Objectives Provide a profile based scheme for customers to configure the OS and Impresario for their platform. The configuration scheme will support different OSes (Linux and MQX) and be compatible with OS s native configuration system. The configuration scheme should be flexible to extend for use with a configuration tool. External Use 16

18 FAS Configuration High-level Configuration Items Profile Sets up the high-level capabilities of the product, primarily based on memory configuration and application-level features. CPU i.mx6, Vybrid, and Kinetis will be officially supported Linux supported on i.mx and Vybrid MQX supported on Vybrid (A5 and M4) and Kinetis Board Ex. Vybrid Auto EVB, i.mx6 SABRE Auto, etc. This determines which peripherals are available, what the memory configuration looks like, IOMUX setup, input configuration, etc. External Use 17

19 FAS Configuration Execution fasconfig graphical configuration tool cd fsl_fas/infrastructure make config External Use 18

20 FAS Configuration Execution Target Configuration External Use 19

21 FAS Configuration Execution Platform Configuration External Use 20

22 FAS Configuration Execution FAS Configuration Metadata Configuration External Use 21

23 FAS Platform Compile and Build cd infrastructure make Generates Linux fakeroot to build against (os/linux) Builds all platform static libraries and optionally creates shared libs mcu-libs/libs/linux/libmcu.so OSA and common library fas/libs/linux/libfas.so fas/third-party/buildroot/lib/linux/libmfihost.so Builds and links applications apps/test_app/test_app External Use 22

24 Freescale Audio Solution Hands-On Test App External Use 23

25 FAS test_app cd apps/test_app/ make local Generates Linux fakeroot to build against (os/linux) Builds all platform static libraries and optionally creates shared libs mcu-libs/libs/linux/libmcu.so OSA and common library fas/libs/linux/libfas.so fas/third-party/buildroot/lib/linux/libmfihost.so Builds and links applications apps/test_app/test_app External Use 24

26 1. Finding a Device SHELL> getdev Get a list of available media devices from Device Manager and print the results. The Device Manager automatically handles the mounting and un-mounting of devices as they are connected and removed from the system as well as sending messages to registered applications to notify of device related events. dev_count = devicemgr_get_all_device_list(10, dev_list); for (i = 0; i < dev_count; i++) { print_device_info(dev_list[i]); } External Use 25

27 2. Player Creation and Setup SHELL> setdev 1 mydevice = devicemgr_get_device_by_id(1); The application can retrieve a device data structure that can then be passed to the player create function to build an audio pipeline appropriate to the device type. player_create(&myplayer, mydevice); - Create audio streamer task - Build the audio streamer pipeline based on device type -- Create source element based on device type -- Create elements for parsing/decoding as required by device type -- Create sink element player_event_register(myplayer, event_id, cb_func, args); -Tell player what events the application should be notified of e.g. changes to the playback state. When a registered event occurs within the streamer pipeline the specified callback function will be executed External Use 26

28 2. Player Creation and Setup (cont.) SHELL> setdev 1 browse_create(mysession, mydevice, browse_type) A default browse session is created by the application when creating a player. The browse session holds device specific context that is used to navigate the contents of devices that support content navigation such as filesystem based devices, Apple devices, or a CD player. Browse sessions can support browsing by metadata or filesystem depending on the type of device in use. External Use 27

29 3. Browsing Contents of a Device A number of functions exist to navigate the device content: SHELL> pwd SHELL> ls d SHELL> ls SHELL> ls f SHELL> filter mp3 wma browse_get_current_folder(session, folder); - Returns path of current browse session browse_get_folders(session, folder_list); Returns a list of folders in the current path browse_get_entries(session, entry_list); Returns a list of audio files and folders in the current path browse_get_tracks(session, track_list) Returns a list of audio files in the current path browse_set_filter_type(session, filter); Set what audio file extensions should be provided in browse results ignoring files that do not match the filter mask. External Use 28

30 3. Browsing Contents of a Device SHELL> cd 1 browse_enter_folder(folder_to_enter); Used to traverse down the browse tree. When browse type is set to filesystem this will set the current directory to a specified subfolder. SHELL> cd.. browse_exit_folder(); Used to traverse up the browse tree. When browse type is set to filesystem this will set the current directory to the parent directory of the current working path. External Use 29

31 4. Using Play Queue The PlayQueue object can be used in conjunction with the browse session to create a list of audio files. A play queue can then be associated with a Player to automatically handle the transition when a track finishes. External Use 30

32 4. Using Play Queue SHELL> mk queue SHELL> addq 2 SHELL> rmq 2 SHELL> move 2 4 SHELL> indexq 2 SHELL> clearq playqueue_create(&myqueue); Create an empty play queue object playqueue_add_track(myqueue, track); Add a track to a play queue object. The track parameter should be obtained from a browse session. playqueue_remove_track(myqueue, index); Remove a track at a specified index from the play queue. playqueue_move_track(myqueue, old_idx, new_idx); Move a track to a new index in the play queue. playqueue_set_current_track_index(myqueue, index); Set the current track index within the play queue playqueue_clear(myqueue); Remove all tracks from the play queue. External Use 31

33 4. Using Play Queue SHELL> shuffle on SHELL> repeat off playqueue_set_shuffle(myqueue, shuffle_state); Set the shuffle mode for the play queue for determining the next track to play. Shuffle can be set to Off, Songs, Albums, Random playqueue_set_repeat(myqueue, repeat_mode); Set the repeat mode for the play queue. Repeat mode can be set to Off, One, All. External Use 32

34 5. Playing Audio SHELL> file a:\test.mp3 SHELL> setq 2 player_set_track(myplayer, track); For use in on-demand mode Set the path for the input source Configure decoders/parsers in the pipeline based on file type player_set_playqueue(myplayer, myqueue); Associates a playqueue object with a player Get the current track from the play queue object Set the path for the input source Configure decoders/parsers in the pipeline based on file type External Use 33

35 5. Playing Audio SHELL> play SHELL> stop SHELL> pause player_control(myplayer, AUDIO_CTRL_PLAY); Set the state of streamer to Play -Pipeline processing is activated - Input file opened - Streamer task actively process input source and outputs audio player_control(myplayer, AUDIO_CTRL_STOP); Set the state of streamer to Stopped -Pipeline processing is deactivated - Input file closed - Streamer task waits for new events from player player_control(myplayer, AUDIO_CTRL_PAUSE); Set the state of streamer to Paused -Pipeline processing is deactivated - Streamer task waits for new events from player External Use 34

36 5. Playing Audio SHELL> next SHELL> prev SHELL> restart player_control(myplayer, AUDIO_CTRL_NEXT_TRACK); Go to the next track in the play queue. -Stop the current track if active -Get track information from the playqueue object -Reconfigure pipeline elements as required -Start playback player_control(myplayer, AUDIO_CTRL_PREV_TRACK); Go to the previous track in the play queue. -Stop the current track if active -Get track information from the playqueue object -Reconfigure pipeline elements as required -Start playback player_control(myplayer, AUDIO_CTRL_RESTART); Restart playback of the current track from the beginning. External Use 35

37 Freescale Audio Solution Hands-On Device Detection and Enumeration External Use 36

38 Custom Application Setup Create directory for application under apps apps/device_test/ Create Makefile External Use 37

39 Custom Application Setup (continued) Create source file setup for a custom FAS application Include the base header files: osa_common.h -> operating system abstraction includes fas_init.h -> initialization routines for FAS Write a main() entry point Looks identical to standard Linux/POSIX main() function signature Initialize FAS with fas_init() Kicks off any configured daemon threads like device manager and input manager Initializes FAS library components Build and install to fakeroot (/nfsroot/ on Host) make local External Use 38

40 Custom Application Setup (continued) Boilerplate Source External Use 39

41 Device Enumeration Hands-On Create Device Enumeration application Begin with boilerplate app setup Add devicemgr.h include Use devicemgr_get_all_device_list() API to get list of attached devices and print them to the display. Extend Device Enumeration application Instead of polling for devices, register a callback handler to receive messages on device connect / disconnect. External Use 40

42 Device Enumeration Hands-On - Code External Use 41

43 Browse and Playback Hands-On Create Browse and Playback Application Begin with device enumeration example Add maestro.h include for Maestro media functionality Build Maestro objects to interface with the device MediaDevice for device-specific interface MediaPlayer for playback control, based on device BrowseSession for device media library browsing Use Maestro APIs to browse the device and extract a playable media track. Use Maestro APIs to play the track. External Use 42

44 Browse and Playback Hands-On - Code External Use 43

45 Browse and Playback Hands-On - Code (continued) External Use 44

46 Browse and Playback Hands-On Extend Browse and Playback Application Create PlayQueue and add items Manipulate tracks in the queue using next/previous Retrieve the playing track info and display Browse to sub-folders and display External Use 45

47 Freescale Semiconductor, Inc. External Use