From acbc451e92fdc5fd58a35061b5127b14e7d762f1 Mon Sep 17 00:00:00 2001 From: Eino-Ville Talvala Date: Sat, 16 Mar 2013 16:53:28 -0700 Subject: Camera3: Documentation additions - Detailed documentation of the 3A state machines (autofocus, autoexposure, auto-whitebalance) - Add error return value for out-of-sequence device calls - Spelling fixes Change-Id: Icc4e1980b1ff058425a42bc665d345070944b173 --- include/hardware/camera3.h | 471 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 462 insertions(+), 9 deletions(-) (limited to 'include/hardware') diff --git a/include/hardware/camera3.h b/include/hardware/camera3.h index d4cae27..68df263 100644 --- a/include/hardware/camera3.h +++ b/include/hardware/camera3.h @@ -37,7 +37,16 @@ * * See camera_common.h for more versioning details. * - * Version history: + * Documentation index: + * S1. Version history + * S2. Startup and operation sequencing + * S3. Operational modes + * S4. 3A modes and state machines + * S5. Error management + */ + +/** + * S1. Version history: * * 1.0: Initial Android camera HAL (Android 4.0) [camera.h]: * @@ -75,7 +84,7 @@ */ /** - * Startup and general expected operation sequence: + * S2. Startup and general expected operation sequence: * * 1. Framework calls camera_module_t->common.open(), which returns a * hardware_device_t structure. @@ -153,7 +162,7 @@ */ /** - * Operational modes: + * S3. Operational modes: * * The camera 3 HAL device can implement one of two possible operational modes; * limited and full. Full support is expected from new higher-end @@ -168,7 +177,7 @@ * * Roughly speaking, limited-mode devices do not allow for application control * of capture settings (3A control only), high-rate capture of high-resolution - * images, raw sensor readout, and support for YUV output streams maximum + * images, raw sensor readout, or support for YUV output streams above maximum * recording resolution (JPEG only for large images). * * ** Details of limited mode behavior: @@ -293,7 +302,447 @@ */ /** - * Error management: + * S4. 3A modes and state machines: + * + * While the actual 3A algorithms are up to the HAL implementation, a high-level + * state machine description is defined by the HAL interface, to allow the HAL + * device and the framework to communicate about the current state of 3A, and to + * trigger 3A events. + * + * When the device is opened, all the individual 3A states must be + * STATE_INACTIVE. Stream configuration does not reset 3A. For example, locked + * focus must be maintained across the configure() call. + * + * Triggering a 3A action involves simply setting the relevant trigger entry in + * the settings for the next request to indicate start of trigger. For example, + * the trigger for starting an autofocus scan is setting the entry + * ANDROID_CONTROL_AF_TRIGGER to ANDROID_CONTROL_AF_TRIGGER_START for one + * request, and cancelling an autofocus scan is triggered by setting + * ANDROID_CONTROL_AF_TRIGGER to ANDROID_CONTRL_AF_TRIGGER_CANCEL. Otherwise, + * the entry will not exist, or be set to ANDROID_CONTROL_AF_TRIGGER_IDLE. Each + * request with a trigger entry set to a non-IDLE value will be treated as an + * independent triggering event. + * + * At the top level, 3A is controlled by the ANDROID_CONTROL_MODE setting, which + * selects between no 3A (ANDROID_CONTROL_MODE_OFF), normal AUTO mode + * (ANDROID_CONTROL_MODE_AUTO), and using the scene mode setting + * (ANDROID_CONTROL_USE_SCENE_MODE). + * + * - In OFF mode, each of the individual AE/AF/AWB modes are effectively OFF, + * and none of the capture controls may be overridden by the 3A routines. + * + * - In AUTO mode, Auto-focus, auto-exposure, and auto-whitebalance all run + * their own independent algorithms, and have their own mode, state, and + * trigger metadata entries, as listed in the next section. + * + * - In USE_SCENE_MODE, the value of the ANDROID_CONTROL_SCENE_MODE entry must + * be used to determine the behavior of 3A routines. In SCENE_MODEs other than + * FACE_PRIORITY, the HAL must override the values of + * ANDROId_CONTROL_AE/AWB/AF_MODE to be the mode it prefers for the selected + * SCENE_MODE. For example, the HAL may prefer SCENE_MODE_NIGHT to use + * CONTINUOUS_FOCUS AF mode. Any user selection of AE/AWB/AF_MODE when scene + * must be ignored for these scene modes. + * + * - For SCENE_MODE_FACE_PRIORITY, the AE/AWB/AF_MODE controls work as in + * ANDROID_CONTROL_MODE_AUTO, but the 3A routines must bias toward metering + * and focusing on any detected faces in the scene. + * + * S4.1. Auto-focus settings and result entries: + * + * Main metadata entries: + * + * ANDROID_CONTROL_AF_MODE: Control for selecting the current autofocus + * mode. Set by the framework in the request settings. + * + * AF_MODE_OFF: AF is disabled; the framework/app directly controls lens + * position. + * + * AF_MODE_AUTO: Single-sweep autofocus. No lens movement unless AF is + * triggered. + * + * AF_MODE_MACRO: Single-sweep up-close autofocus. No lens movement unless + * AF is triggered. + * + * AF_MODE_CONTINUOUS_VIDEO: Smooth continuous focusing, for recording + * video. Triggering immediately locks focus in current + * position. Canceling resumes cotinuous focusing. + * + * AF_MODE_CONTINUOUS_PICTURE: Fast continuous focusing, for + * zero-shutter-lag still capture. Triggering locks focus once currently + * active sweep concludes. Canceling resumes continuous focusing. + * + * AF_MODE_EDOF: Advanced extended depth of field focusing. There is no + * autofocus scan, so triggering one or canceling one has no effect. + * Images are focused automatically by the HAL. + * + * ANDROID_CONTROL_AF_STATE: Dynamic metadata describing the current AF + * algorithm state, reported by the HAL in the result metadata. + * + * AF_STATE_INACTIVE: No focusing has been done, or algorithm was + * reset. Lens is not moving. Always the state for MODE_OFF or MODE_EDOF. + * When the device is opened, it must start in this state. + * + * AF_STATE_PASSIVE_SCAN: A continuous focus algorithm is currently scanning + * for good focus. The lens is moving. + * + * AF_STATE_PASSIVE_FOCUSED: A continuous focus algorithm believes it is + * well focused. The lens is not moving. The HAL may spontaneously leave + * this state. + * + * AF_STATE_ACTIVE_SCAN: A scan triggered by the user is underway. + * + * AF_STATE_FOCUSED_LOCKED: The AF algorithm believes it is focused. The + * lens is not moving. + * + * AF_STATE_NOT_FOCUSED_LOCKED: The AF algorithm has been unable to + * focus. The lens is not moving. + * + * ANDROID_CONTROL_AF_TRIGGER: Control for starting an autofocus scan, the + * meaning of which is mode- and state- dependent. Set by the framework in + * the request settings. + * + * AF_TRIGGER_IDLE: No current trigger. + * + * AF_TRIGGER_START: Trigger start of AF scan. Effect is mode and state + * dependent. + * + * AF_TRIGGER_CANCEL: Cancel current AF scan if any, and reset algorithm to + * default. + * + * Additional metadata entries: + * + * ANDROID_CONTROL_AF_REGIONS: Control for selecting the regions of the FOV + * that should be used to determine good focus. This applies to all AF + * modes that scan for focus. Set by the framework in the request + * settings. + * + * S4.2. Auto-exposure settings and result entries: + * + * Main metadata entries: + * + * ANDROID_CONTROL_AE_MODE: Control for selecting the current auto-exposure + * mode. Set by the framework in the request settings. + * + * AE_MODE_OFF: Autoexposure is disabled; the user controls exposure, gain, + * frame duration, and flash. + * + * AE_MODE_ON: Standard autoexposure, with flash control disabled. User may + * set flash to fire or to torch mode. + * + * AE_MODE_ON_AUTO_FLASH: Standard autoexposure, with flash on at HAL's + * discretion for precapture and still capture. User control of flash + * disabled. + * + * AE_MODE_ON_ALWAYS_FLASH: Standard autoexposure, with flash always fired + * for capture, and at HAL's discretion for precapture.. User control of + * flash disabled. + * + * AE_MODE_ON_AUTO_FLASH_REDEYE: Standard autoexposure, with flash on at + * HAL's discretion for precapture and still capture. Use a flash burst + * at end of precapture sequence to reduce redeye in the final + * picture. User control of flash disabled. + * + * ANDROID_CONTROL_AE_STATE: Dynamic metadata describing the current AE + * algorithm state, reported by the HAL in the result metadata. + * + * AE_STATE_INACTIVE: Initial AE state after mode switch. When the device is + * opened, it must start in this state. + * + * AE_STATE_SEARCHING: AE is not converged to a good value, and is adjusting + * exposure parameters. + * + * AE_STATE_CONVERGED: AE has found good exposure values for the current + * scene, and the exposure parameters are not changing. HAL may + * spontaneously leave this state to search for better solution. + * + * AE_STATE_LOCKED: AE has been locked with the AE_LOCK control. Exposure + * values are not changing. + * + * AE_STATE_FLASH_REQUIRED: The HAL has converged exposure, but believes + * flash is required for a sufficiently bright picture. Used for + * determining if a zero-shutter-lag frame can be used. + * + * AE_STATE_PRECAPTURE: The HAL is in the middle of a precapture + * sequence. Depending on AE mode, this mode may involve firing the + * flash for metering, or a burst of flash pulses for redeye reduction. + * + * ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER: Control for starting a metering + * sequence before capturing a high-quality image. Set by the framework in + * the request settings. + * + * PRECAPTURE_TRIGGER_IDLE: No current trigger. + * + * PRECAPTURE_TRIGGER_START: Start a precapture sequence. The HAL should + * use the subsequent requests to measure good exposure/white balance + * for an upcoming high-resolution capture. + * + * Additional metadata entries: + * + * ANDROID_CONTROL_AE_LOCK: Control for locking AE controls to their current + * values + * + * ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION: Control for adjusting AE + * algorithm target brightness point. + * + * ANDROID_CONTROL_AE_TARGET_FPS_RANGE: Control for selecting the target frame + * rate range for the AE algorithm. The AE routine cannot change the frame + * rate to be outside these bounds. + * + * ANDROID_CONTROL_AE_REGIONS: Control for selecting the regions of the FOV + * that should be used to determine good exposure levels. This applies to + * all AE modes besides OFF. + * + * S4.3. Auto-whitebalance settings and result entries: + * + * Main metadata entries: + * + * ANDROID_CONTROL_AWB_MODE: Control for selecting the current white-balance + * mode. + * + * AWB_MODE_OFF: Auto-whitebalance is disabled. User controls color matrix. + * + * AWB_MODE_AUTO: Automatic white balance is enabled; 3A controls color + * transform, possibly using more complex transforms than a simple + * matrix. + * + * AWB_MODE_INCANDESCENT: Fixed white balance settings good for indoor + * incandescent (tungsten) lighting, roughly 2700K. + * + * AWB_MODE_FLUORESCENT: Fixed white balance settings good for fluorescent + * lighting, roughly 5000K. + * + * AWB_MODE_WARM_FLUORESCENT: Fixed white balance settings good for + * fluorescent lighting, roughly 3000K. + * + * AWB_MODE_DAYLIGHT: Fixed white balance settings good for daylight, + * roughly 5500K. + * + * AWB_MODE_CLOUDY_DAYLIGHT: Fixed white balance settings good for clouded + * daylight, roughly 6500K. + * + * AWB_MODE_TWILIGHT: Fixed white balance settings good for + * near-sunset/sunrise, roughly 15000K. + * + * AWB_MODE_SHADE: Fixed white balance settings good for areas indirectly + * lit by the sun, roughly 7500K. + * + * ANDROID_CONTROL_AWB_STATE: Dynamic metadata describing the current AWB + * algorithm state, reported by the HAL in the result metadata. + * + * AWB_STATE_INACTIVE: Initial AWB state after mode switch. When the device + * is opened, it must start in this state. + * + * AWB_STATE_SEARCHING: AWB is not converged to a good value, and is + * changing color adjustment parameters. + * + * AWB_STATE_CONVERGED: AWB has found good color adjustment values for the + * current scene, and the parameters are not changing. HAL may + * spontaneously leave this state to search for better solution. + * + * AWB_STATE_LOCKED: AWB has been locked with the AWB_LOCK control. Color + * adjustment values are not changing. + * + * Additional metadata entries: + * + * ANDROID_CONTROL_AWB_LOCK: Control for locking AWB color adjustments to + * their current values. + * + * ANDROID_CONTROL_AWB_REGIONS: Control for selecting the regions of the FOV + * that should be used to determine good color balance. This applies only + * to auto-WB mode. + * + * S4.4. General state machine transition notes + * + * Switching between AF, AE, or AWB modes always resets the algorithm's state + * to INACTIVE. Similarly, switching between CONTROL_MODE or + * CONTROL_SCENE_MODE if CONTROL_MODE == USE_SCENE_MODE resets all the + * algorithm states to INACTIVE. + * + * The tables below are per-mode. + * + * S4.5. AF state machines + * + * mode = AF_MODE_OFF or AF_MODE_EDOF + *| state | trans. cause | new state | notes | + *+--------------------+---------------+--------------------+------------------+ + *| INACTIVE | | | AF is disabled | + *+--------------------+---------------+--------------------+------------------+ + * + * mode = AF_MODE_AUTO or AF_MODE_MACRO + *| state | trans. cause | new state | notes | + *+--------------------+---------------+--------------------+------------------+ + *| INACTIVE | AF_TRIGGER | ACTIVE_SCAN | Start AF sweep | + *| | | | Lens now moving | + *+--------------------+---------------+--------------------+------------------+ + *| ACTIVE_SCAN | AF sweep done | FOCUSED_LOCKED | If AF successful | + *| | | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| ACTIVE_SCAN | AF sweep done | NOT_FOCUSED_LOCKED | If AF successful | + *| | | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| ACTIVE_SCAN | AF_CANCEL | INACTIVE | Cancel/reset AF | + *| | | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| FOCUSED_LOCKED | AF_CANCEL | INACTIVE | Cancel/reset AF | + *+--------------------+---------------+--------------------+------------------+ + *| FOCUSED_LOCKED | AF_TRIGGER | ACTIVE_SCAN | Start new sweep | + *| | | | Lens now moving | + *+--------------------+---------------+--------------------+------------------+ + *| NOT_FOCUSED_LOCKED | AF_CANCEL | INACTIVE | Cancel/reset AF | + *+--------------------+---------------+--------------------+------------------+ + *| NOT_FOCUSED_LOCKED | AF_TRIGGER | ACTIVE_SCAN | Start new sweep | + *| | | | Lens now moving | + *+--------------------+---------------+--------------------+------------------+ + *| All states | mode change | INACTIVE | | + *+--------------------+---------------+--------------------+------------------+ + * + * mode = AF_MODE_CONTINUOUS_VIDEO + *| state | trans. cause | new state | notes | + *+--------------------+---------------+--------------------+------------------+ + *| INACTIVE | HAL initiates | PASSIVE_SCAN | Start AF scan | + *| | new scan | | Lens now moving | + *+--------------------+---------------+--------------------+------------------+ + *| INACTIVE | AF_TRIGGER | NOT_FOCUSED_LOCKED | AF state query | + *| | | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| PASSIVE_SCAN | HAL completes | PASSIVE_FOCUSED | End AF scan | + *| | current scan | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| PASSIVE_SCAN | AF_TRIGGER | FOCUSED_LOCKED | Immediate trans. | + *| | | | if focus is good | + *| | | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| PASSIVE_SCAN | AF_TRIGGER | NOT_FOCUSED_LOCKED | Immediate trans. | + *| | | | if focus is bad | + *| | | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| PASSIVE_SCAN | AF_CANCEL | INACTIVE | Reset lens | + *| | | | position | + *| | | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| PASSIVE_FOCUSED | HAL initiates | PASSIVE_SCAN | Start AF scan | + *| | new scan | | Lens now moving | + *+--------------------+---------------+--------------------+------------------+ + *| PASSIVE_FOCUSED | AF_TRIGGER | FOCUSED_LOCKED | Immediate trans. | + *| | | | if focus is good | + *| | | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| PASSIVE_FOCUSED | AF_TRIGGER | NOT_FOCUSED_LOCKED | Immediate trans. | + *| | | | if focus is bad | + *| | | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| FOCUSED_LOCKED | AF_TRIGGER | FOCUSED_LOCKED | No effect | + *+--------------------+---------------+--------------------+------------------+ + *| FOCUSED_LOCKED | AF_CANCEL | INACTIVE | Restart AF scan | + *+--------------------+---------------+--------------------+------------------+ + *| NOT_FOCUSED_LOCKED | AF_TRIGGER | NOT_FOCUSED_LOCKED | No effect | + *+--------------------+---------------+--------------------+------------------+ + *| NOT_FOCUSED_LOCKED | AF_CANCEL | INACTIVE | Restart AF scan | + *+--------------------+---------------+--------------------+------------------+ + * + * mode = AF_MODE_CONTINUOUS_PICTURE + *| state | trans. cause | new state | notes | + *+--------------------+---------------+--------------------+------------------+ + *| INACTIVE | HAL initiates | PASSIVE_SCAN | Start AF scan | + *| | new scan | | Lens now moving | + *+--------------------+---------------+--------------------+------------------+ + *| INACTIVE | AF_TRIGGER | NOT_FOCUSED_LOCKED | AF state query | + *| | | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| PASSIVE_SCAN | HAL completes | PASSIVE_FOCUSED | End AF scan | + *| | current scan | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| PASSIVE_SCAN | AF_TRIGGER | FOCUSED_LOCKED | Eventual trans. | + *| | | | once focus good | + *| | | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| PASSIVE_SCAN | AF_TRIGGER | NOT_FOCUSED_LOCKED | Eventual trans. | + *| | | | if cannot focus | + *| | | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| PASSIVE_SCAN | AF_CANCEL | INACTIVE | Reset lens | + *| | | | position | + *| | | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| PASSIVE_FOCUSED | HAL initiates | PASSIVE_SCAN | Start AF scan | + *| | new scan | | Lens now moving | + *+--------------------+---------------+--------------------+------------------+ + *| PASSIVE_FOCUSED | AF_TRIGGER | FOCUSED_LOCKED | Immediate trans. | + *| | | | if focus is good | + *| | | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| PASSIVE_FOCUSED | AF_TRIGGER | NOT_FOCUSED_LOCKED | Immediate trans. | + *| | | | if focus is bad | + *| | | | Lens now locked | + *+--------------------+---------------+--------------------+------------------+ + *| FOCUSED_LOCKED | AF_TRIGGER | FOCUSED_LOCKED | No effect | + *+--------------------+---------------+--------------------+------------------+ + *| FOCUSED_LOCKED | AF_CANCEL | INACTIVE | Restart AF scan | + *+--------------------+---------------+--------------------+------------------+ + *| NOT_FOCUSED_LOCKED | AF_TRIGGER | NOT_FOCUSED_LOCKED | No effect | + *+--------------------+---------------+--------------------+------------------+ + *| NOT_FOCUSED_LOCKED | AF_CANCEL | INACTIVE | Restart AF scan | + *+--------------------+---------------+--------------------+------------------+ + * + * S4.6. AE and AWB state machines + * + * The AE and AWB state machines are mostly identical. AE has additional + * FLASH_REQUIRED and PRECAPTURE states. So rows below that refer to those two + * states should be ignored for the AWB state machine. + * + * mode = AE_MODE_OFF / AWB mode not AUTO + *| state | trans. cause | new state | notes | + *+--------------------+---------------+--------------------+------------------+ + *| INACTIVE | | | AE/AWB disabled | + *+--------------------+---------------+--------------------+------------------+ + * + * mode = AE_MODE_ON_* / AWB_MODE_AUTO + *| state | trans. cause | new state | notes | + *+--------------------+---------------+--------------------+------------------+ + *| INACTIVE | HAL initiates | SEARCHING | | + *| | AE/AWB scan | | | + *+--------------------+---------------+--------------------+------------------+ + *| INACTIVE | AE/AWB_LOCK | LOCKED | values locked | + *| | on | | | + *+--------------------+---------------+--------------------+------------------+ + *| SEARCHING | HAL finishes | CONVERGED | good values, not | + *| | AE/AWB scan | | changing | + *+--------------------+---------------+--------------------+------------------+ + *| SEARCHING | HAL finishes | FLASH_REQUIRED | converged but too| + *| | AE scan | | dark w/o flash | + *+--------------------+---------------+--------------------+------------------+ + *| SEARCHING | AE/AWB_LOCK | LOCKED | values locked | + *| | on | | | + *+--------------------+---------------+--------------------+------------------+ + *| CONVERGED | HAL initiates | SEARCHING | values locked | + *| | AE/AWB scan | | | + *+--------------------+---------------+--------------------+------------------+ + *| CONVERGED | AE/AWB_LOCK | LOCKED | values locked | + *| | on | | | + *+--------------------+---------------+--------------------+------------------+ + *| LOCKED | AE/AWB_LOCK | SEARCHING | values not good | + *| | off | | after unlock | + *+--------------------+---------------+--------------------+------------------+ + *| LOCKED | AE/AWB_LOCK | CONVERGED | values good | + *| | off | | after unlock | + *+--------------------+---------------+--------------------+------------------+ + *| LOCKED | AE_LOCK | FLASH_REQUIRED | exposure good, | + *| | off | | but too dark | + *+--------------------+---------------+--------------------+------------------+ + *| All AE states | PRECAPTURE_ | PRECAPTURE | Start precapture | + *| | START | | sequence | + *+--------------------+---------------+--------------------+------------------+ + *| PRECAPTURE | Sequence done.| CONVERGED | Ready for high- | + *| | AE_LOCK off | | quality capture | + *+--------------------+---------------+--------------------+------------------+ + *| PRECAPTURE | Sequence done.| LOCKED | Ready for high- | + *| | AE_LOCK on | | quality capture | + *+--------------------+---------------+--------------------+------------------+ + * + */ + +/** + * S5. Error management: * * Camera HAL device ops functions that have a return value will all return * -ENODEV / NULL in case of a serious error. This means the device cannot @@ -302,6 +751,10 @@ * the close() method can be called successfully. All other methods will return * -ENODEV / NULL. * + * If a device op is called in the wrong sequence, for example if the framework + * calls configure_streams() is called before initialize(), the device must + * return -ENOSYS from the call, and do nothing. + * * Transient errors in image capture must be reported through notify() as follows: * * - The failure of an entire capture to occur must be reported by the HAL by @@ -320,8 +773,8 @@ * metadata could not be produced, it should be NULL. If some buffers could not * be filled, their sync fences must be set to the error state. * - * Invalid input aguments result in -EINVAL from the appropriate methods. In - * that case, the framework should act as if that call had never been made. + * Invalid input arguments result in -EINVAL from the appropriate methods. In + * that case, the framework must act as if that call had never been made. * */ @@ -1288,7 +1741,7 @@ typedef struct camera3_device_ops { * buffer. * * NULL: In case of a fatal error. After this is returned, only - * the close() method can be called succesfully by the + * the close() method can be called successfully by the * framework. */ const camera_metadata_t* (*construct_default_request_settings)( @@ -1348,7 +1801,7 @@ typedef struct camera3_device_ops { /** * get_metadata_vendor_tag_ops: * - * Get methods to query for vendor extension metadata tag infomation. The + * Get methods to query for vendor extension metadata tag information. The * HAL should fill in all the vendor tag operation methods, or leave ops * unchanged if no vendor tags are defined. * -- cgit v1.1