107 lines · c
1/* SPDX-License-Identifier: GPL-2.0 */2/*3 * The Virtual DVB test driver serves as a reference DVB driver and helps4 * validate the existing APIs in the media subsystem. It can also aid5 * developers working on userspace applications.6 *7 * Copyright (C) 2020 Daniel W. S. Almeida8 */9 10#ifndef VIDTV_TS_H11#define VIDTV_TS_H12 13#include <linux/types.h>14 15#define TS_SYNC_BYTE 0x4716#define TS_PACKET_LEN 18817#define TS_PAYLOAD_LEN 18418#define TS_NULL_PACKET_PID 0x1fff19#define TS_CC_MAX_VAL 0x0f /* 4 bits */20#define TS_LAST_VALID_PID 819121#define TS_FILL_BYTE 0xff /* the byte used in packet stuffing */22 23struct vidtv_mpeg_ts_adaption {24 u8 length;25 struct {26 u8 extension:1;27 u8 private_data:1;28 u8 splicing_point:1;29 u8 OPCR:1;30 u8 PCR:1;31 u8 priority:1;32 u8 random_access:1;33 u8 discontinued:1;34 } __packed;35 u8 data[];36} __packed;37 38struct vidtv_mpeg_ts {39 u8 sync_byte;40 __be16 bitfield; /* tei: 1, payload_start:1 priority: 1, pid:13 */41 struct {42 u8 continuity_counter:4;43 u8 payload:1;44 u8 adaptation_field:1;45 u8 scrambling:2;46 } __packed;47} __packed;48 49/**50 * struct pcr_write_args - Arguments for the pcr_write_into function.51 * @dest_buf: The buffer to write into.52 * @dest_offset: The byte offset into the buffer.53 * @pid: The TS PID for the PCR packets.54 * @buf_sz: The size of the buffer in bytes.55 * @continuity_counter: The TS continuity_counter.56 * @pcr: A sample from the system clock.57 */58struct pcr_write_args {59 void *dest_buf;60 u32 dest_offset;61 u16 pid;62 u32 buf_sz;63 u8 *continuity_counter;64 u64 pcr;65};66 67/**68 * struct null_packet_write_args - Arguments for the null_write_into function69 * @dest_buf: The buffer to write into.70 * @dest_offset: The byte offset into the buffer.71 * @buf_sz: The size of the buffer in bytes.72 * @continuity_counter: The TS continuity_counter.73 */74struct null_packet_write_args {75 void *dest_buf;76 u32 dest_offset;77 u32 buf_sz;78 u8 *continuity_counter;79};80 81/* Increment the continuity counter */82void vidtv_ts_inc_cc(u8 *continuity_counter);83 84/**85 * vidtv_ts_null_write_into - Write a TS null packet into a buffer.86 * @args: the arguments to use when writing.87 *88 * This function will write a null packet into a buffer. This is usually used to89 * pad TS streams.90 *91 * Return: The number of bytes written into the buffer.92 */93u32 vidtv_ts_null_write_into(struct null_packet_write_args args);94 95/**96 * vidtv_ts_pcr_write_into - Write a PCR packet into a buffer.97 * @args: the arguments to use when writing.98 *99 * This function will write a PCR packet into a buffer. This is used to100 * synchronize the clocks between encoders and decoders.101 *102 * Return: The number of bytes written into the buffer.103 */104u32 vidtv_ts_pcr_write_into(struct pcr_write_args args);105 106#endif //VIDTV_TS_H107