diff options
| -rw-r--r-- | src/input/input_plugin.h | 33 |
1 files changed, 29 insertions, 4 deletions
diff --git a/src/input/input_plugin.h b/src/input/input_plugin.h index bccde4b57..a3d015582 100644 --- a/src/input/input_plugin.h +++ b/src/input/input_plugin.h @@ -17,7 +17,7 @@ * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA * - * $Id: input_plugin.h,v 1.39 2002/11/20 11:57:43 mroi Exp $ + * $Id: input_plugin.h,v 1.40 2002/12/15 22:18:09 rockyb Exp $ */ #ifndef HAVE_INPUT_PLUGIN_H @@ -80,7 +80,13 @@ struct input_class_s { struct input_plugin_s { /* - * return capabilities of input source + * return capabilities of the current playable entity. See + * get_current_pos below for a description of a "playable entity" + * Capabilities a created by "OR"ing a mask of constants listed + * below which start "INPUT_CAP". Depending on the mask value + * returned, some of the routines below may or may not get + * called. For example, if INPUT_CAP_SEEKABLE is not set, the seek + * routine will not get called. */ uint32_t (*get_capabilities) (input_plugin_t *this); @@ -115,13 +121,32 @@ struct input_plugin_s { /* - * return length of input (-1 => unlimited, e.g. stream) + * return number of bytes in the next playable entity or -1 if the + * input is unlimited, as would be the case in a stream. + * + * A "playable entity" tends to be the entities listed in a playback + * list or the units on which playback control generally works on. + * It might be the number of bytes in a VCD "segment" or "track" (if + * the track has no "entry" subdivisions), or the number of bytes in + * a PS (Program Segment or "Chapter") of a DVD. If there are no + * subdivisions of the input medium and it is considered one + * indivisible entity, it would be the byte count of that entity; + * for example, the length in bytes of an MPEG file. + + * This length information is used, for example when in setting the + * absolute or relative play position or possibly calculating the + * bit rate. */ off_t (*get_length) (input_plugin_t *this); /* - * return block size of input source (if supported, 0 otherwise) + * return block size in bytes of next complete playable entity (if + * supported, 0 otherwise). See the description above under + * get_length for a description of a "complete playable entity". + * + * The block size is used in allocation buffers; when block reads + * are performed, this is the requested number of bytes to read. */ uint32_t (*get_blocksize) (input_plugin_t *this); |