8.4.0.2. FFmpeg Decoding Interface
|
(packages/ffmpeg/ffmpeg.lsh) |
8.4.0.2.0. (av-open-input-file filename)
|
(packages/ffmpeg/ffmpeg.lsh) |
See: AvInputFile
Open the multimedia file filename
using the FFmpeg library and returns an instance of class
AvInputFile .
8.4.0.2.1. (av-open-video-source filename)
|
(packages/ffmpeg/ffmpeg.lsh) |
See: VideoSource
See: AvVideoSource
Open the multimedia file filename
using the FFmpeg library and returns a
AvVideoSource object connected to the first video stream in
the file.
8.4.0.2.2. (av-open-audio-source filename)
|
(packages/ffmpeg/ffmpeg.lsh) |
See: AudioSource
See: AvAudioSource
Open the multimedia file filename
using the FFmpeg library and returns a
AvAudioSource object connected to the first audio stream in
the file.
8.4.0.2.3. AvInputFile
|
(packages/ffmpeg/ffmpeg.lsh) |
See: (av-open-input-file filename
)
Class AvInputFile is a handle for
reading a multimedia file. It is best created using the utility function
av-open-input-file . Each multimedia file contains one or
more streams. Each stream is either an audio stream or a video stream.
This class defines several useful slots:
- Slots audio-streams and
video-streams contain the number of streams of each type.
- The geometry of the first video stream is stored in fields
frame-height , frame-width
, frame-aspect-ratio .
- The sampling rate and the number of channels of the first audio
stream are stored in slots audio-sample-rate
and audio-channels .
8.4.0.2.3.0. (new AvInputFile)
|
[CLASS] (packages/ffmpeg/ffmpeg.lsh) |
Create a new empty instance of class AvInputFile
. Calling method open associates this
handle with a multimedia file. Various FFmpeg options can be set by
defining certain slots of this object before calling
open .
8.4.0.2.3.1. (==> avinputfile get-number-of-streams)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Return the total number of streams in the multimedia file.
8.4.0.2.3.2. (==> avinputfile get-stream-codec-type n)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the type of the stream number n
. The return value is one of the constants named
@CODEC_TYPE_XXX . This includes
@CODEC_TYPE_VIDEO or @CODEC_TYPE_AUDIO
.
8.4.0.2.3.3. (==> avinputfile get-stream-codec-id n)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the identifier of the codec for stream number
n . The return value is one of the constants named
@CODEC_ID_XXX .
8.4.0.2.3.4. (==> avinputfile get-format-name)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns a string describing the multimedia file format.
8.4.0.2.3.5. (==> avinputfile get-start-time)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the first presentation time stamp for the multimedia file.
Presentation time stamps are real numbers expressed in seconds.
8.4.0.2.3.6. (==> avinputfile get-duration)
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[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the duration of the multimedia file expressed in seconds.
8.4.0.2.3.7. (==> avinputfile open filename)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Associate the empty avinputfile object
with the multimedia file named filename
. This function checks the file format and the file codecs. It causes an
error if the file cannot be decoded by the ffmpeg library.
8.4.0.2.3.8. (==> avinputfile pump)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Method pump reads data from the
multimedia file and distributes it to the various streams.
8.4.0.2.4. AvAudioSource
|
(packages/ffmpeg/ffmpeg.lsh) |
See: AudioSource
This subclass of AudioSource provides
access to the audio streams of a multimedia file represented by an
instance of AvInputFile .
WARNING : Currently, this class is not usable.
8.4.0.2.4.0. (new AvAudioSource avinputfile n)
|
[CLASS] (packages/ffmpeg/ffmpeg.lsh) |
Creates a new AvAudioSource object for
accessing stream number n in the
multimedia file avinputfile . Stream
number n must of course be an audio
stream.
8.4.0.2.4.1. (==> avaudiosource get-codec-name)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns a string containing the name of the codec for this audio stream.
8.4.0.2.4.2. (==> avaudiosource get-codec-id)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the identifier of the codec for this audio stream. This function
returns one of the @CODEC_ID_XXX
constant.
8.4.0.2.4.3. (==> avaudiosource get-start-time)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the first presentation time stamp for this audio stream.
Presentation time stamps are real numbers expressed in seconds.
8.4.0.2.4.4. (==> avaudiosource get-duration)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the duration of this audio stream expressed in seconds.
8.4.0.2.5. AvVideoSource
|
(packages/ffmpeg/ffmpeg.lsh) |
See: VideoSource
This subclass of VideoSource provides
access to the audio streams of a multimedia file represented by an
instance of AvInputFile .
The current frame geometry is available in slots
frame-height , frame-width
, and frame-aspect-ratio .
8.4.0.2.5.0. (new AvVideoSource avinputfile n)
|
[CLASS] (packages/ffmpeg/ffmpeg.lsh) |
Creates a new AvVideoSource object for
accessing stream number n in the
multimedia file avinputfile . Stream
number n must of course be a video
stream.
8.4.0.2.5.1. (==> avvideosource get-codec-name)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns a string containing the name of the codec for this video stream.
8.4.0.2.5.2. (==> avvideosource get-codec-id)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the identifier of the codec for this video stream. This function
returns one of the @CODEC_ID_XXX
constant.
8.4.0.2.5.3. (==> avvideosource get-start-time)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the first presentation time stamp for this video stream.
Presentation time stamps are real numbers expressed in seconds.
8.4.0.2.5.4. (==> avvideosource get-duration)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the duration of this video stream expressed in seconds.
8.4.0.2.5.5. (==> avvideosource get-frame-rate)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the frame rate of this video stream expressed in frames per
seconds.
8.4.0.2.5.6. (==> avvideosource get-frame-period)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the delay between consecutive frames expressed in seconds. This
is the inverse of the frame rate.
8.4.0.2.5.7. (==> avvideosource get-number-of-frames)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the number of frames estimated from the frame rate and stream
duration. This is only an estimate because certain files have variable
frame rate, and because certain frames last more than one period.
8.4.0.2.5.8. (==> avvideosource nextframe)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Method nextframe obtains the next
video frame. It returns t if a new
frame can be accessed, using the frame access methods
get-frame-xxx , and returns ()
when reaching the end of the video stream.
After initializing the video source, this method must be called once in
order to access the first video frame.
8.4.0.2.5.9. (==> avvideosource get-frame-pts)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the presentation time stamp of the current frame. The
presentation time stamp is a real number expressed in seconds. Calling
this function before the first call to nextframe
gives the starting time of the movie.
8.4.0.2.5.10. (==> avvideosource get-frame-number)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the presentation frame number of the current frame.
8.4.0.2.5.11. (==> avvideosource get-frame-gray)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the gray level image associated with the current frame as a two
dimensional matrix of unsigned bytes.
8.4.0.2.5.12. (==> avvideosource get-frame-rgba)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the RBGA image associated with the current frame as a three
dimensional matrix of unsigned bytes. The last dimentsion contains four
elements: three color components (R, G, B) and one alpha channel (A).
8.4.0.2.5.13. (==> avvideosource get-frame-yuv)
|
[MSG] (packages/ffmpeg/ffmpeg.lsh) |
Returns the YUV image associated with the current frame as a three
dimensional matrix of unsigned bytes. The last dimentsion contains three
elements, one per color component (Y, U, V).