[media] DocBook: document typedef dmx_ts_cb at demux.h

 * Callback functions

 */

/**

 * typedef dmx_ts_cb - DVB demux TS filter callback function prototype

 *

 * @buffer1:		Pointer to the start of the filtered TS packets.

 * @buffer1_length:	Length of the TS data in buffer1.

 * @buffer2:		Pointer to the tail of the filtered TS packets, or NULL.

 * @buffer2_length:	Length of the TS data in buffer2.

 * @source:		Indicates which TS feed is the source of the callback.

 *

 * This function callback prototype, provided by the client of the demux API,

 * is called from the demux code. The function is only called when filtering

 * on ae TS feed has been enabled using the start_filtering() function at

 * the &dmx_demux.

 * Any TS packets that match the filter settings are copied to a circular

 * buffer. The filtered TS packets are delivered to the client using this

 * callback function. The size of the circular buffer is controlled by the

 * circular_buffer_size parameter of the &dmx_ts_feed.@set function.

 * It is expected that the @buffer1 and @buffer2 callback parameters point to

 * addresses within the circular buffer, but other implementations are also

 * possible. Note that the called party should not try to free the memory

 * the @buffer1 and @buffer2 parameters point to.

 *

 * When this function is called, the @buffer1 parameter typically points to

 * the start of the first undelivered TS packet within a circular buffer.

 * The @buffer2 buffer parameter is normally NULL, except when the received

 * TS packets have crossed the last address of the circular buffer and

 * ”wrapped” to the beginning of the buffer. In the latter case the @buffer1

 * parameter would contain an address within the circular buffer, while the

 * @buffer2 parameter would contain the first address of the circular buffer.

 * The number of bytes delivered with this function (i.e. @buffer1_length +

 * @buffer2_length) is usually equal to the value of callback_length parameter

 * given in the set() function, with one exception: if a timeout occurs before

 * receiving callback_length bytes of TS data, any undelivered packets are

 * immediately delivered to the client by calling this function. The timeout

 * duration is controlled by the set() function in the TS Feed API.

 *

 * If a TS packet is received with errors that could not be fixed by the

 * TS-level forward error correction (FEC), the Transport_error_indicator

 * flag of the TS packet header should be set. The TS packet should not be

 * discarded, as the error can possibly be corrected by a higher layer

 * protocol. If the called party is slow in processing the callback, it

 * is possible that the circular buffer eventually fills up. If this happens,

 * the demux driver should discard any TS packets received while the buffer

 * is full and return -EOVERFLOW.

 *

 * The type of data returned to the callback can be selected by the

 * &dmx_ts_feed.@set function. The type parameter decides if the raw

 * TS packet (TS_PACKET) or just the payload (TS_PACKET|TS_PAYLOAD_ONLY)

 * should be returned. If additionally the TS_DECODER bit is set the stream

 * will also be sent to the hardware MPEG decoder.

 *

 * Return:

 * 	0, on success;

 * 	-EOVERFLOW, on buffer overflow.

 */

typedef int (*dmx_ts_cb)(const u8 *buffer1,

			 size_t buffer1_length,

			 const u8 *buffer2,