// @see: ngx_rtmp_mpegts.c // TODO: support full mpegts feature in future. class SrsMpegtsWriter { public: static int write_frame(int fd, SrsMpegtsFrame* frame, SrsCodecBuffer* buffer) { int ret = ERROR_SUCCESS; if (!buffer->bytes || buffer->size <= 0) { return ret; } char* last = buffer->bytes + buffer->size; char* pos = buffer->bytes; bool first = true; while (pos < last) { static char packet[188]; char* p = packet; frame->cc++; // sync_byte; //8bits *p++ = 0x47; // pid; //13bits *p++ = (frame->pid >> 8) & 0x1f; // payload_unit_start_indicator; //1bit if (first) { p[-1] |= 0x40; } *p++ = frame->pid; // transport_scrambling_control; //2bits // adaption_field_control; //2bits, 0x01: PayloadOnly // continuity_counter; //4bits *p++ = 0x10 | (frame->cc & 0x0f); if (first) { first = false; if (frame->key) { p[-1] |= 0x20; // Both Adaption and Payload *p++ = 7; // size *p++ = 0x50; // random access + PCR p = write_pcr(p, frame->dts - SRS_HLS_DELAY); } // PES header // packet_start_code_prefix; //24bits, '00 00 01' *p++ = 0x00; *p++ = 0x00; *p++ = 0x01; //8bits *p++ = frame->sid; // pts(33bits) need 5bytes. u_int8_t header_size = 5; u_int8_t flags = 0x80; // pts // dts(33bits) need 5bytes also if (frame->dts != frame->pts) { header_size += 5; flags |= 0x40; // dts } // 3bytes: flag fields from PES_packet_length to PES_header_data_length int pes_size = (last - pos) + header_size + 3; if (pes_size > 0xffff) { /**  * when actual packet length > 0xffff(65535),  * which exceed the max u_int16_t packet length,  * use 0 packet length, the next unit start indicates the end of packet.  */ pes_size = 0; } // PES_packet_length; //16bits *p++ = (pes_size >> 8); *p++ = pes_size; // PES_scrambling_control; //2bits, '10' // PES_priority; //1bit // data_alignment_indicator; //1bit // copyright; //1bit // original_or_copy; //1bit *p++ = 0x80; /* H222 */ // PTS_DTS_flags; //2bits // ESCR_flag; //1bit // ES_rate_flag; //1bit // DSM_trick_mode_flag; //1bit // additional_copy_info_flag; //1bit // PES_CRC_flag; //1bit // PES_extension_flag; //1bit *p++ = flags; // PES_header_data_length; //8bits *p++ = header_size; // pts; // 33bits p = write_pts(p, flags >> 6, frame->pts + SRS_HLS_DELAY); // dts; // 33bits if (frame->dts != frame->pts) { p = write_pts(p, 1, frame->dts + SRS_HLS_DELAY); } } int body_size = sizeof(packet) - (p - packet); int in_size = last - pos; if (body_size <= in_size) { memcpy(p, pos, body_size); pos += body_size; } else { p = fill_stuff(p, packet, body_size, in_size); memcpy(p, pos, in_size); pos = last; } // write ts packet if (::write(fd, packet, sizeof(packet)) != sizeof(packet)) { ret = ERROR_HLS_WRITE_FAILED; srs_error("write ts file failed. ret=%d", ret); return ret; } } return ret; } };