OpenShot Library | libopenshot  0.2.5
Public Member Functions | Public Attributes | List of all members
openshot::Timeline Class Reference

This class represents a timeline. More...

#include <Timeline.h>

Inheritance diagram for openshot::Timeline:
openshot::TimelineBase openshot::ReaderBase

Public Member Functions

void AddClip (openshot::Clip *clip)
 Add an openshot::Clip to the timeline. More...
 
void AddEffect (openshot::EffectBase *effect)
 Add an effect to the timeline. More...
 
void ApplyJsonDiff (std::string value)
 Apply a special formatted JSON object, which represents a change to the timeline (add, update, delete) This is primarily designed to keep the timeline (and its child objects... such as clips and effects) in sync with another application... such as OpenShot Video Editor (http://www.openshot.org). More...
 
void ApplyMapperToClips ()
 Apply the timeline's framerate and samplerate to all clips. More...
 
bool AutoMapClips ()
 Determine if clips are automatically mapped to the timeline's framerate and samplerate. More...
 
void AutoMapClips (bool auto_map)
 Automatically map all clips to the timeline's framerate and samplerate. More...
 
void ClearAllCache ()
 Clear all cache for this timeline instance, and all clips, mappers, and readers under it. More...
 
std::list< openshot::Clip * > Clips ()
 Return a list of clips on the timeline. More...
 
void Close () override
 Close the timeline reader (and any resources it was consuming) More...
 
std::list< openshot::EffectBase * > Effects ()
 Return the list of effects on the timeline. More...
 
openshot::CacheBaseGetCache () override
 Get the cache object used by this reader. More...
 
openshot::ClipGetClip (const std::string &id)
 Look up a single clip by ID. More...
 
openshot::EffectBaseGetClipEffect (const std::string &id)
 Look up a clip effect by ID. More...
 
openshot::EffectBaseGetEffect (const std::string &id)
 Look up a timeline effect by ID. More...
 
std::shared_ptr< openshot::FrameGetFrame (int64_t requested_frame) override
 
int64_t GetMaxFrame ()
 Look up the end frame number of the latest element on the timeline. More...
 
double GetMaxTime ()
 Look up the end time of the latest timeline element. More...
 
bool IsOpen () override
 Determine if reader is open or closed. More...
 
std::string Json () const override
 Get and Set JSON methods. More...
 
Json::Value JsonValue () const override
 Generate Json::Value for this object. More...
 
std::string Name () override
 Return the type name of the class. More...
 
void Open () override
 Open the reader (and start consuming resources) More...
 
void RemoveClip (openshot::Clip *clip)
 Remove an openshot::Clip from the timeline. More...
 
void RemoveEffect (openshot::EffectBase *effect)
 Remove an effect from the timeline. More...
 
void SetCache (openshot::CacheBase *new_cache)
 
void SetJson (const std::string value) override
 Load JSON string into this object. More...
 
void SetJsonValue (const Json::Value root) override
 Load Json::Value into this object. More...
 
void SetMaxSize (int width, int height)
 
 Timeline (int width, int height, openshot::Fraction fps, int sample_rate, int channels, openshot::ChannelLayout channel_layout)
 Default Constructor for the timeline (which configures the default frame properties) More...
 
 Timeline (const std::string &projectPath, bool convert_absolute_paths)
 Project-file constructor for the timeline. More...
 
virtual ~Timeline ()
 
- Public Member Functions inherited from openshot::TimelineBase
 TimelineBase ()
 Constructor for the base timeline. More...
 
- Public Member Functions inherited from openshot::ReaderBase
void DisplayInfo ()
 Display file information in the standard output stream (stdout) More...
 
openshot::ClipBaseParentClip ()
 Parent clip object of this reader (which can be unparented and NULL) More...
 
void ParentClip (openshot::ClipBase *new_clip)
 Set parent clip object of this reader. More...
 
 ReaderBase ()
 Constructor for the base reader, where many things are initialized. More...
 
virtual ~ReaderBase ()=default
 

Public Attributes

openshot::Color color
 Background color of timeline canvas. More...
 
openshot::Keyframe viewport_scale
 Curve representing the scale of the viewport (0 to 100) More...
 
openshot::Keyframe viewport_x
 Curve representing the x coordinate for the viewport. More...
 
openshot::Keyframe viewport_y
 Curve representing the y coordinate for the viewport. More...
 
- Public Attributes inherited from openshot::TimelineBase
int preview_height
 Optional preview width of timeline image. If your preview window is smaller than the timeline, it's recommended to set this. More...
 
int preview_width
 Optional preview width of timeline image. If your preview window is smaller than the timeline, it's recommended to set this. More...
 
- Public Attributes inherited from openshot::ReaderBase
openshot::ReaderInfo info
 Information about the current media file. More...
 

Additional Inherited Members

- Protected Attributes inherited from openshot::ReaderBase
openshot::ClipBaseclip
 Pointer to the parent clip instance (if any) More...
 
juce::CriticalSection getFrameCriticalSection
 Section lock for multiple threads. More...
 
juce::CriticalSection processingCriticalSection
 

Detailed Description

This class represents a timeline.

The timeline is one of the most important features of a video editor, and controls all aspects of how video, image, and audio clips are combined together, and how the final video output will be rendered. It has a collection of layers and clips, that arrange, sequence, and generate the final video output.

The following graphic displays a timeline, and how clips can be arranged, scaled, and layered together. It also demonstrates how the viewport can be scaled smaller than the canvas, which can be used to zoom and pan around the canvas (i.e. pan & scan).

Timeline_Layers.png

The following graphic displays how the playhead determines which frames to combine and layer.

Playhead.png

Lets take a look at what the code looks like:

// Create a Timeline
Timeline t(1280, // width
720, // height
Fraction(25,1), // framerate
44100, // sample rate
2 // channels
);
// Create some clips
Clip c1(new ImageReader("MyAwesomeLogo.jpeg"));
Clip c2(new FFmpegReader("BackgroundVideo.webm"));
// CLIP 1 (logo) - Set some clip properties (with Keyframes)
c1.Position(0.0); // Set the position or location (in seconds) on the timeline
c1.gravity = GRAVITY_LEFT; // Set the alignment / gravity of the clip (position on the screen)
c1.scale = SCALE_CROP; // Set the scale mode (how the image is resized to fill the screen)
c1.Layer(1); // Set the layer of the timeline (higher layers cover up images of lower layers)
c1.Start(0.0); // Set the starting position of the video (trim the left side of the video)
c1.End(16.0); // Set the ending position of the video (trim the right side of the video)
c1.alpha.AddPoint(1, 0.0); // Set the alpha to transparent on frame #1
c1.alpha.AddPoint(500, 0.0); // Keep the alpha transparent until frame #500
c1.alpha.AddPoint(565, 1.0); // Animate the alpha from transparent to visible (between frame #501 and #565)
// CLIP 2 (background video) - Set some clip properties (with Keyframes)
c2.Position(0.0); // Set the position or location (in seconds) on the timeline
c2.Start(10.0); // Set the starting position of the video (trim the left side of the video)
c2.Layer(0); // Set the layer of the timeline (higher layers cover up images of lower layers)
c2.alpha.AddPoint(1, 1.0); // Set the alpha to visible on frame #1
c2.alpha.AddPoint(150, 0.0); // Animate the alpha to transparent (between frame 2 and frame #150)
c2.alpha.AddPoint(360, 0.0, LINEAR); // Keep the alpha transparent until frame #360
c2.alpha.AddPoint(384, 1.0); // Animate the alpha to visible (between frame #360 and frame #384)
// Add clips to timeline
t.AddClip(&c1);
t.AddClip(&c2);
// Open the timeline reader
t.Open();
// Get frame number 1 from the timeline (This will generate a new frame, made up from the previous clips and settings)
std::shared_ptr<Frame> f = t.GetFrame(1);
// Now that we have an openshot::Frame object, lets have some fun!
f->Display(); // Display the frame on the screen
// Close the timeline reader
t.Close();

Definition at line 167 of file Timeline.h.

Constructor & Destructor Documentation

◆ Timeline() [1/2]

Timeline::Timeline ( int  width,
int  height,
openshot::Fraction  fps,
int  sample_rate,
int  channels,
openshot::ChannelLayout  channel_layout 
)

Default Constructor for the timeline (which configures the default frame properties)

Parameters
widthThe image width of generated openshot::Frame objects
heightThe image height of generated openshot::Frame objects
fpsThe frame rate of the generated video
sample_rateThe audio sample rate
channelsThe number of audio channels
channel_layoutThe channel layout (i.e. mono, stereo, 3 point surround, etc...)

Definition at line 36 of file Timeline.cpp.

◆ Timeline() [2/2]

Timeline::Timeline ( const std::string &  projectPath,
bool  convert_absolute_paths 
)

Project-file constructor for the timeline.

Loads a JSON structure from a file path, and initializes the timeline described within.

Parameters
projectPathThe path of the UTF-8 *.osp project file (JSON contents). Contents will be loaded automatically.
convert_absolute_pathsShould all paths be converted to absolute paths (relative to the location of projectPath)

Definition at line 87 of file Timeline.cpp.

◆ ~Timeline()

Timeline::~Timeline ( )
virtual

Definition at line 219 of file Timeline.cpp.

Member Function Documentation

◆ AddClip()

void Timeline::AddClip ( openshot::Clip clip)

Add an openshot::Clip to the timeline.

Parameters
clipAdd an openshot::Clip to the timeline. A clip can contain any type of Reader.

Definition at line 244 of file Timeline.cpp.

Referenced by ApplyJsonDiff(), SetJsonValue(), and openshot::QtPlayer::SetSource().

◆ AddEffect()

void Timeline::AddEffect ( openshot::EffectBase effect)

Add an effect to the timeline.

Parameters
effectAdd an effect to the timeline. An effect can modify the audio or video of an openshot::Frame.

Definition at line 267 of file Timeline.cpp.

Referenced by ApplyJsonDiff(), and SetJsonValue().

◆ ApplyJsonDiff()

void Timeline::ApplyJsonDiff ( std::string  value)

Apply a special formatted JSON object, which represents a change to the timeline (add, update, delete) This is primarily designed to keep the timeline (and its child objects... such as clips and effects) in sync with another application... such as OpenShot Video Editor (http://www.openshot.org).

Parameters
valueA JSON string containing a key, value, and type of change.

Definition at line 1073 of file Timeline.cpp.

◆ ApplyMapperToClips()

void Timeline::ApplyMapperToClips ( )

Apply the timeline's framerate and samplerate to all clips.

Definition at line 382 of file Timeline.cpp.

◆ AutoMapClips() [1/2]

bool openshot::Timeline::AutoMapClips ( )
inline

Determine if clips are automatically mapped to the timeline's framerate and samplerate.

Definition at line 256 of file Timeline.h.

◆ AutoMapClips() [2/2]

void openshot::Timeline::AutoMapClips ( bool  auto_map)
inline

Automatically map all clips to the timeline's framerate and samplerate.

Definition at line 259 of file Timeline.h.

◆ ClearAllCache()

void Timeline::ClearAllCache ( )

Clear all cache for this timeline instance, and all clips, mappers, and readers under it.

Definition at line 1470 of file Timeline.cpp.

Referenced by ApplyJsonDiff(), ApplyMapperToClips(), and GetFrame().

◆ Clips()

std::list<openshot::Clip*> openshot::Timeline::Clips ( )
inline

Return a list of clips on the timeline.

Definition at line 265 of file Timeline.h.

◆ Close()

void Timeline::Close ( )
overridevirtual

Close the timeline reader (and any resources it was consuming)

Implements openshot::ReaderBase.

Definition at line 657 of file Timeline.cpp.

Referenced by SetJsonValue(), and ~Timeline().

◆ Effects()

std::list<openshot::EffectBase*> openshot::Timeline::Effects ( )
inline

Return the list of effects on the timeline.

Definition at line 285 of file Timeline.h.

◆ GetCache()

openshot::CacheBase* openshot::Timeline::GetCache ( )
inlineoverridevirtual

Get the cache object used by this reader.

Implements openshot::ReaderBase.

Definition at line 288 of file Timeline.h.

◆ GetClip()

openshot::Clip * Timeline::GetClip ( const std::string &  id)

Look up a single clip by ID.

Definition at line 292 of file Timeline.cpp.

◆ GetClipEffect()

openshot::EffectBase * Timeline::GetClipEffect ( const std::string &  id)

Look up a clip effect by ID.

Definition at line 315 of file Timeline.cpp.

◆ GetEffect()

openshot::EffectBase * Timeline::GetEffect ( const std::string &  id)

Look up a timeline effect by ID.

Definition at line 304 of file Timeline.cpp.

◆ GetFrame()

std::shared_ptr< Frame > Timeline::GetFrame ( int64_t  requested_frame)
overridevirtual

Get an openshot::Frame object for a specific frame number of this timeline.

Returns
The requested frame (containing the image)
Parameters
requested_frameThe frame number that is requested.

Implements openshot::ReaderBase.

Definition at line 689 of file Timeline.cpp.

◆ GetMaxFrame()

int64_t Timeline::GetMaxFrame ( )

Look up the end frame number of the latest element on the timeline.

Definition at line 346 of file Timeline.cpp.

◆ GetMaxTime()

double Timeline::GetMaxTime ( )

Look up the end time of the latest timeline element.

Definition at line 328 of file Timeline.cpp.

Referenced by GetMaxFrame().

◆ IsOpen()

bool openshot::Timeline::IsOpen ( )
inlineoverridevirtual

Determine if reader is open or closed.

Implements openshot::ReaderBase.

Definition at line 309 of file Timeline.h.

◆ Json()

std::string Timeline::Json ( ) const
overridevirtual

Get and Set JSON methods.

Generate JSON string of this object

Implements openshot::ReaderBase.

Definition at line 943 of file Timeline.cpp.

◆ JsonValue()

Json::Value Timeline::JsonValue ( ) const
overridevirtual

Generate Json::Value for this object.

Implements openshot::ReaderBase.

Definition at line 950 of file Timeline.cpp.

Referenced by Json().

◆ Name()

std::string openshot::Timeline::Name ( )
inlineoverridevirtual

Return the type name of the class.

Implements openshot::ReaderBase.

Definition at line 312 of file Timeline.h.

◆ Open()

void Timeline::Open ( )
overridevirtual

Open the reader (and start consuming resources)

Implements openshot::ReaderBase.

Definition at line 677 of file Timeline.cpp.

Referenced by SetJsonValue(), and openshot::QtPlayer::SetSource().

◆ RemoveClip()

void Timeline::RemoveClip ( openshot::Clip clip)

Remove an openshot::Clip from the timeline.

Parameters
clipRemove an openshot::Clip from the timeline.

Definition at line 286 of file Timeline.cpp.

Referenced by ApplyJsonDiff().

◆ RemoveEffect()

void Timeline::RemoveEffect ( openshot::EffectBase effect)

Remove an effect from the timeline.

Parameters
effectRemove an effect from the timeline.

Definition at line 280 of file Timeline.cpp.

Referenced by ApplyJsonDiff().

◆ SetCache()

void Timeline::SetCache ( openshot::CacheBase new_cache)

Set the cache object used by this reader. You must now manage the lifecycle of this cache object though (Timeline will not delete it for you).

Definition at line 930 of file Timeline.cpp.

◆ SetJson()

void Timeline::SetJson ( const std::string  value)
overridevirtual

Load JSON string into this object.

Implements openshot::ReaderBase.

Definition at line 984 of file Timeline.cpp.

Referenced by Timeline().

◆ SetJsonValue()

void Timeline::SetJsonValue ( const Json::Value  root)
overridevirtual

Load Json::Value into this object.

Implements openshot::ReaderBase.

Definition at line 1004 of file Timeline.cpp.

Referenced by SetJson().

◆ SetMaxSize()

void Timeline::SetMaxSize ( int  width,
int  height 
)

Set Max Image Size (used for performance optimization). Convenience function for setting Settings::Instance()->MAX_WIDTH and Settings::Instance()->MAX_HEIGHT.

Definition at line 1497 of file Timeline.cpp.

Referenced by Timeline().

Member Data Documentation

◆ color

openshot::Color openshot::Timeline::color

Background color of timeline canvas.

Definition at line 306 of file Timeline.h.

Referenced by ApplyJsonDiff(), GetFrame(), JsonValue(), and Timeline().

◆ viewport_scale

openshot::Keyframe openshot::Timeline::viewport_scale

Curve representing the scale of the viewport (0 to 100)

Definition at line 301 of file Timeline.h.

Referenced by ApplyJsonDiff(), JsonValue(), and Timeline().

◆ viewport_x

openshot::Keyframe openshot::Timeline::viewport_x

Curve representing the x coordinate for the viewport.

Definition at line 302 of file Timeline.h.

Referenced by ApplyJsonDiff(), JsonValue(), and Timeline().

◆ viewport_y

openshot::Keyframe openshot::Timeline::viewport_y

Curve representing the y coordinate for the viewport.

Definition at line 303 of file Timeline.h.

Referenced by ApplyJsonDiff(), JsonValue(), and Timeline().


The documentation for this class was generated from the following files: