ARRI ALEXA 35, Руководство пользователя, Страница: 49 / 117

Recording 49
Compact Drive LED States
LED State Media State
Solid Green Drive is in standby, ready to record and safe to remove.
Solid Red Read/write access during Playback or Recording. Do not remove the drive.
Info: As recording is stopped, it takes a few seconds to finalize the recorded clip. During this time, the drive
should not be removed.
Blue flashing Drive is being loaded or unloaded.
Red flashing Drive error, see MENU > Alerts for details.
Off Drive cannot be accessed. Please try reinserting the drive. If the problem persists, check the drive state with
Codex Device Manager.
Media Info
► Select
MENU > Info > Media Info
for additional information on the inserted medium.
12.2 Recording Codec
MXF (Material eXchange Format)
Both ARRIRAW and Apple ProRes files are recorded in an MXF (Material eXchange Format) container.
An MXF container file can "wrap" different types of video and audio material along with associated
metadata. The internal structure of these files is defined by the Operational Patterns (OP). Our cameras
create MXF files with OP1a structure, which packages picture, sound and metadata into a single file.
This structure is ideal for both camera acquisition and archiving, since audio, video and metadata is
always kept together and virtually no data gets lost if recording is unexpectedly interrupted. OP1a also
is a streaming format, which means that even incomplete files can be repaired and accessed up to the
last recorded frame.
ARRIRAW
ARRIRAW data delivers unencrypted, uncompressed and uncompromised image quality. It offers
the highest achievable resolution, the camera's natural color response and exposure latitude as
uncompressed and unprocessed sensor data. ARRIRAW images have only one channel. A color
reconstruction algorithm calculates the missing components of each pixel based on the type and
position of the array of colored filters (Bayer pattern) on the camera sensor.
ARRIRAW de-bayering is available through the ARRI Imaging SDK only, which is implemented in the
ARRI Reference Tool (ART) and most of the major post production tools for dailies processing and
mastering.
The camera will automatically calculate a CRC32C checksum for the image data inside each
ARRIRAW frame. This checksum is recorded as part of the image header and can be used by software
like the ARRI Reference Tool, to verify that the ARRIRAW image content has not changed during any
copy step. Note that this checksum does not validate the entire file, only the image data. Note that
during the download from the Compact Drive to a computer or afterwards it is possible to reduce the
size of ARRIRAW files by up to 40% using Codex High Density Encoding (HDE) technology with the
ARRIRAW HDE Transcoder app.
Apple ProRes
Recording in Apple ProRes is a cost efficient alternative to shooting ARRIRAW, as it requires less
storage space and no further processing in post.
Info: Apple ProRes is a variable bit rate (VBR) codec. Depending on the content of your images the
remaining recording time on the recording media can be shorter or longer than indicated by the camera.