COM Objects > TagsReader object > Methods > TagsReader.MP4

Remarks

Creates a graphic file, of a given graphic format, containing the picture stored inside a MP4 picture frame.

For further details about methods related to tags reading refer to the TagsReader object.

For details about the reading of tags see the How to read TAG information in sound files tutorial.

Syntax

[Visual Basic]

control.TagsReader.MP4_PictureFrameFileGet (

nIndex as Integer,

strPathname as String,

nFormat as enumGraphicFormats,

nFormatParameter as Long

) as enumErrorCodes

[C++]

short control.TagsReader.MP4_PictureFrameFileGet (

short nIndex,

BSTR strPathname,

short nFormat,

long nFormatParameter

);

Parameter

Description

nIndex

Zero-based index of the picture frame. The total number of picture frames available inside the MP4 tag can be obtained through a call to the TagsReader.MP4_PictureFrameCountGet method.

strPathname

String representing the absolute pathname of the output graphic file.

nFormat

Graphic format of the output graphic file.

Supported values are the following:

Mnemonic value	Value	Meaning
GRAPHIC_FORMAT_ORIGINAL	-1	Original format used to store the picture inside the tag. When this option is selected, the output graphic file will be an exact copy of the contents of the picture frame. You can determine the original graphic format, through its MIME type, by calling the TagsReader.MP4_PictureFrameMimeGet method; this information can be also useful to determine the file extension to use when composing the strPathname parameter above.
GRAPHIC_FORMAT_BMP	0	The output file will be converted to BMP format
GRAPHIC_FORMAT_JPEG	1	The output file will be converted to JPEG format
GRAPHIC_FORMAT_PNG	2	The output file will be converted to PNG format
GRAPHIC_FORMAT_GIF	3	The output file will be converted to GIF format
GRAPHIC_FORMAT_TIFF	4	The output file will be converted to TIFF format

nFormatParameter

Eventual parameter required by the chosen graphic format.

When the nFormat parameter is set to GRAPHIC_FORMAT_JPEG, this parameter defines the JPEG compression factor whose range can be in the range from 0 (Maximum compression, Lower Quality) to 100 (Minimum compression, Higher Quality).

Return value

Value	Meaning

Negative value	An error occurred (see the LastError property for further error details)
enumErrorCodes.NOERROR (0)	The method call was successful.