// But it also means that Shairport Sync's buffers must be sufficient to hold all the
// entire lead-time's amount of audio in case the device has a zero-sized buffer.
-
- if ((play_enabled != 0) &&
- (have_valid_time != 0)
- // (audio_decoded_buffer_below_desired_length != 0) &&
- && (lead_time * 1E-9 < (config.audio_decoded_buffer_desired_length + 0.1))
- // && (audio_decoded_buffer_below_desired_length != 0)
- ) {
-
- very_early_packets_signalled = 0; // reset very early packet warning signaller
-
- // try to identify blocks that are timed to before the last buffer, and drop 'em
- int64_t time_from_last_buffer_time =
- buffer_should_be_time - previous_buffer_should_be_time;
-
- if ((packets_played_in_this_sequence == 0) || (time_from_last_buffer_time > 0)) {
-
- payload_length = 0;
- if (ssrc_is_recognised(payload_ssrc) != 0) {
- // prepare_decoding_chain(conn, payload_ssrc);
- unsigned long long new_payload_length = 0;
- payload_pointer = m + leading_free_space_length;
- if (lead_time >= 0) { // only decipher the packet if it's not too late
- int response = -1; // guess that there is a problem
- if (conn->session_key != NULL) {
- unsigned char nonce[12];
- memset(nonce, 0, sizeof(nonce));
- memcpy(
- nonce + 4, packet + nread - 8,
- 8); // front-pad the 8-byte nonce received to get the 12-byte nonce expected
-
- // https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/chacha20-poly1305/ietf_chacha20-poly1305_construction
- // Note: the eight-byte nonce must be front-padded out to 12 bytes.
-
- // Leave leading_free_space_length bytes at the start for possible headers like an
- // ADTS header (7 bytes)
- memset(m, 0, leading_free_space_length);
- response = crypto_aead_chacha20poly1305_ietf_decrypt(
- payload_pointer, // where the decrypted payload will start
- &new_payload_length, // mlen_p
- NULL, // nsec,
- packet +
- 12, // the ciphertext starts 12 bytes in and is followed by the MAC tag,
- nread - (8 + 12), // clen -- the last 8 bytes are the nonce
- packet + 4, // authenticated additional data
- 8, // authenticated additional data length
- nonce,
- conn->session_key); // *k
- if (response != 0)
- debug(1, "Error decrypting audio packet %u -- packet length %zd.", seq_no,
- nread);
- } else {
- debug(2, "No session key, so the audio packet can not be deciphered -- skipped.");
- }
-
- if ((response == 0) && (new_payload_length > 0)) {
- // now we have the deciphered block, so send it to the player if we can
- payload_length = new_payload_length;
-
- if (ssrc_is_aac(payload_ssrc)) {
- payload_pointer =
- payload_pointer - 7; // including the 7-byte leader for the ADTS
- payload_length = payload_length + 7;
-
- // now, fill in the 7-byte ADTS information, which seems to be needed by the
- // decoder we made room for it in the front of the buffer by filling from m + 7.
- int channelConfiguration = 2; // 2: 2 channels: front-left, front-right
- if (payload_ssrc == AAC_48000_F24_5P1)
- channelConfiguration = 6; // 6: 6 channels: front-center, front-left,
- // front-right, back-left, back-right, LFE-channel
- else if (payload_ssrc == AAC_48000_F24_7P1)
- channelConfiguration =
- 7; // 7: 8 channels: front-center, front-left, front-right,
- // side-left, side-right, back-left, back-right, LFE-channel
- addADTStoPacket(payload_pointer, payload_length, conn->input_rate,
- channelConfiguration);
- }
- int mute =
- ((packets_played_in_this_sequence == 0) && (ssrc_is_aac(payload_ssrc)));
- if (mute) {
- debug(2, "Connection %d: muting first AAC block -- block %u -- timestamp %u.",
- conn->connection_number, seq_no, timestamp);
- }
- int32_t timestamp_difference = 0;
- if (packets_played_in_this_sequence == 0) {
- // first_block_in_this_sequence = seq_no;
- first_timestamp_in_this_sequence = timestamp;
- debug(2,
- "Connection %d: "
- "first block %u, first timestamp %u.",
- conn->connection_number, seq_no, timestamp);
+
+ if (have_valid_time != 0) {
+ if ((play_enabled != 0) && (lead_time * 1E-9 < (config.audio_decoded_buffer_desired_length + 0.1))) {
+ // && (audio_decoded_buffer_below_desired_length != 0)
+ very_early_packets_signalled = 0; // reset very early packet warning signaller
+
+ // try to identify blocks that are timed to before the last buffer, and drop 'em
+ int64_t time_from_last_buffer_time =
+ buffer_should_be_time - previous_buffer_should_be_time;
+
+ if ((packets_played_in_this_sequence == 0) || (time_from_last_buffer_time > 0)) {
+
+ payload_length = 0;
+ if (ssrc_is_recognised(payload_ssrc) != 0) {
+ // prepare_decoding_chain(conn, payload_ssrc);
+ unsigned long long new_payload_length = 0;
+ payload_pointer = m + leading_free_space_length;
+ if (lead_time >= 0) { // only decipher the packet if it's not too late
+ int response = -1; // guess that there is a problem
+ if (conn->session_key != NULL) {
+ unsigned char nonce[12];
+ memset(nonce, 0, sizeof(nonce));
+ memcpy(
+ nonce + 4, packet + nread - 8,
+ 8); // front-pad the 8-byte nonce received to get the 12-byte nonce expected
+
+ // https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/chacha20-poly1305/ietf_chacha20-poly1305_construction
+ // Note: the eight-byte nonce must be front-padded out to 12 bytes.
+
+ // Leave leading_free_space_length bytes at the start for possible headers like an
+ // ADTS header (7 bytes)
+ memset(m, 0, leading_free_space_length);
+ response = crypto_aead_chacha20poly1305_ietf_decrypt(
+ payload_pointer, // where the decrypted payload will start
+ &new_payload_length, // mlen_p
+ NULL, // nsec,
+ packet +
+ 12, // the ciphertext starts 12 bytes in and is followed by the MAC tag,
+ nread - (8 + 12), // clen -- the last 8 bytes are the nonce
+ packet + 4, // authenticated additional data
+ 8, // authenticated additional data length
+ nonce,
+ conn->session_key); // *k
+ if (response != 0)
+ debug(1, "Error decrypting audio packet %u -- packet length %zd.", seq_no,
+ nread);
} else {
- timestamp_difference = timestamp - expected_timestamp;
- if (timestamp_difference != 0) {
+ debug(2, "No session key, so the audio packet can not be deciphered -- skipped.");
+ }
+
+ if ((response == 0) && (new_payload_length > 0)) {
+ // now we have the deciphered block, so send it to the player if we can
+ payload_length = new_payload_length;
+
+ if (ssrc_is_aac(payload_ssrc)) {
+ payload_pointer =
+ payload_pointer - 7; // including the 7-byte leader for the ADTS
+ payload_length = payload_length + 7;
+
+ // now, fill in the 7-byte ADTS information, which seems to be needed by the
+ // decoder we made room for it in the front of the buffer by filling from m + 7.
+ int channelConfiguration = 2; // 2: 2 channels: front-left, front-right
+ if (payload_ssrc == AAC_48000_F24_5P1)
+ channelConfiguration = 6; // 6: 6 channels: front-center, front-left,
+ // front-right, back-left, back-right, LFE-channel
+ else if (payload_ssrc == AAC_48000_F24_7P1)
+ channelConfiguration =
+ 7; // 7: 8 channels: front-center, front-left, front-right,
+ // side-left, side-right, back-left, back-right, LFE-channel
+ addADTStoPacket(payload_pointer, payload_length, conn->input_rate,
+ channelConfiguration);
+ }
+ int mute =
+ ((packets_played_in_this_sequence == 0) && (ssrc_is_aac(payload_ssrc)));
+ if (mute) {
+ debug(2, "Connection %d: muting first AAC block -- block %u -- timestamp %u.",
+ conn->connection_number, seq_no, timestamp);
+ }
+ int32_t timestamp_difference = 0;
+ if (packets_played_in_this_sequence == 0) {
+ // first_block_in_this_sequence = seq_no;
+ first_timestamp_in_this_sequence = timestamp;
debug(2,
"Connection %d: "
- "unexpected timestamp in block %u. Actual: %u, expected: %u "
- "difference: %d, "
- "%f ms. "
- "Positive means later, i.e. a gap. First timestamp was %u, payload "
- "type: \"%s\".",
- conn->connection_number, seq_no, timestamp, expected_timestamp,
- timestamp_difference, 1000.0 * timestamp_difference / conn->input_rate,
- first_timestamp_in_this_sequence, get_ssrc_name(payload_ssrc));
- // mute the first packet after a discontinuity
- if (ssrc_is_aac(payload_ssrc)) {
+ "first block %u, first timestamp %u.",
+ conn->connection_number, seq_no, timestamp);
+ } else {
+ timestamp_difference = timestamp - expected_timestamp;
+ if (timestamp_difference != 0) {
debug(2,
- "Connection %d: muting first AAC block -- block %u -- following a "
- "timestamp discontinuity, timestamp %u.",
- conn->connection_number, seq_no, timestamp);
- mute = 1;
+ "Connection %d: "
+ "unexpected timestamp in block %u. Actual: %u, expected: %u "
+ "difference: %d, "
+ "%f ms. "
+ "Positive means later, i.e. a gap. First timestamp was %u, payload "
+ "type: \"%s\".",
+ conn->connection_number, seq_no, timestamp, expected_timestamp,
+ timestamp_difference, 1000.0 * timestamp_difference / conn->input_rate,
+ first_timestamp_in_this_sequence, get_ssrc_name(payload_ssrc));
+ // mute the first packet after a discontinuity
+ if (ssrc_is_aac(payload_ssrc)) {
+ debug(2,
+ "Connection %d: muting first AAC block -- block %u -- following a "
+ "timestamp discontinuity, timestamp %u.",
+ conn->connection_number, seq_no, timestamp);
+ mute = 1;
+ }
}
}
- }
- int skip_this_block = 0;
- if (timestamp_difference < 0) {
-
- // uncomment this to work back to replace buffers that have been already decoded
- // and placed in the player queue with the incoming new buffers this is a bit
- // trickier, but maybe the new buffers are better than the previous ones they
- // will replace (?)
- /*
- seq_t revised_seqno = get_revised_seqno(conn, timestamp);
- if (revised_seqno != sequence_number_for_player) {
- debug(1, "revised seqno calculated: conn->ab_read: %u, revised_seqno: %u,
- conn->ab_write: %u.", conn->ab_read, revised_seqno, conn->ab_write);
- clear_buffers_from(conn, revised_seqno);
- sequence_number_for_player = revised_seqno;
- timestamp_difference = 0;
+ int skip_this_block = 0;
+ if (timestamp_difference < 0) {
+
+ // uncomment this to work back to replace buffers that have been already decoded
+ // and placed in the player queue with the incoming new buffers this is a bit
+ // trickier, but maybe the new buffers are better than the previous ones they
+ // will replace (?)
+ /*
+ seq_t revised_seqno = get_revised_seqno(conn, timestamp);
+ if (revised_seqno != sequence_number_for_player) {
+ debug(1, "revised seqno calculated: conn->ab_read: %u, revised_seqno: %u,
+ conn->ab_write: %u.", conn->ab_read, revised_seqno, conn->ab_write);
+ clear_buffers_from(conn, revised_seqno);
+ sequence_number_for_player = revised_seqno;
+ timestamp_difference = 0;
+ }
+ */
+
+ // uncomment this to drop incoming new buffers that are too old and for whose
+ // timings buffers have already been decoded and placed in the player queue this
+ // is easier, but maybe the new late buffers are better than the previous ones
+ // (?)
+
+ int32_t abs_timestamp_difference = -timestamp_difference;
+ if ((size_t)abs_timestamp_difference > get_ssrc_block_length(payload_ssrc)) {
+ skip_this_block = 1;
+ debug(2,
+ "skipping block %u because it is too old. Timestamp "
+ "difference: %d, length of block: %zu.",
+ seq_no, timestamp_difference, get_ssrc_block_length(payload_ssrc));
+ }
}
- */
-
- // uncomment this to drop incoming new buffers that are too old and for whose
- // timings buffers have already been decoded and placed in the player queue this
- // is easier, but maybe the new late buffers are better than the previous ones
- // (?)
-
- int32_t abs_timestamp_difference = -timestamp_difference;
- if ((size_t)abs_timestamp_difference > get_ssrc_block_length(payload_ssrc)) {
- skip_this_block = 1;
- debug(2,
- "skipping block %u because it is too old. Timestamp "
- "difference: %d, length of block: %zu.",
- seq_no, timestamp_difference, get_ssrc_block_length(payload_ssrc));
+ if (skip_this_block == 0) {
+ uint32_t packet_size = player_put_packet(
+ payload_ssrc, sequence_number_for_player, timestamp, payload_pointer,
+ payload_length, mute, timestamp_difference, conn);
+ debug(4, "block %u, timestamp %u, length %u sent to the player.", seq_no,
+ timestamp, packet_size);
+ sequence_number_for_player++; // simply increment
+ expected_timestamp = timestamp + packet_size; // for the next time
+ packets_played_in_this_sequence++;
}
}
- if (skip_this_block == 0) {
- uint32_t packet_size = player_put_packet(
- payload_ssrc, sequence_number_for_player, timestamp, payload_pointer,
- payload_length, mute, timestamp_difference, conn);
- debug(4, "block %u, timestamp %u, length %u sent to the player.", seq_no,
- timestamp, packet_size);
- sequence_number_for_player++; // simply increment
- expected_timestamp = timestamp + packet_size; // for the next time
- packets_played_in_this_sequence++;
+ } else {
+ debug(3,
+ "skipped deciphering block %u with timestamp %u because its lead time is "
+ "out of range at %f "
+ "seconds.",
+ seq_no, timestamp, lead_time * 1.0E-9);
+ uint32_t currentAnchorRTP = 0;
+ uint64_t currentAnchorLocalTime = 0;
+ if (get_ptp_anchor_local_time_info(conn, ¤tAnchorRTP,
+ ¤tAnchorLocalTime) == clock_ok) {
+ debug(3, "anchorRTP: %u, anchorLocalTime: %" PRIu64 ".", currentAnchorRTP,
+ currentAnchorLocalTime);
+ } else {
+ debug(3, "Clock not okay");
}
}
} else {
- debug(3,
- "skipped deciphering block %u with timestamp %u because its lead time is "
- "out of range at %f "
- "seconds.",
- seq_no, timestamp, lead_time * 1.0E-9);
- uint32_t currentAnchorRTP = 0;
- uint64_t currentAnchorLocalTime = 0;
- if (get_ptp_anchor_local_time_info(conn, ¤tAnchorRTP,
- ¤tAnchorLocalTime) == clock_ok) {
- debug(3, "anchorRTP: %u, anchorLocalTime: %" PRIu64 ".", currentAnchorRTP,
- currentAnchorLocalTime);
- } else {
- debug(3, "Clock not okay");
- }
+ debug(2, "Unrecognised or invalid ssrc: %s.", get_ssrc_name(payload_ssrc));
}
} else {
- debug(2, "Unrecognised or invalid ssrc: %s.", get_ssrc_name(payload_ssrc));
+ debug(1, "dropping buffer that should have played before the last actually played.");
}
+ new_audio_block_needed = 1; // the block has been used up and is no longer current
} else {
- debug(1, "dropping buffer that should have played before the last actually played.");
+ if ((very_early_packets_signalled == 0) && (lead_time * 1E-9 > (config.audio_decoded_buffer_desired_length + 0.2))) {
+ debug(1,
+ "incoming frame suddenly (?) has a lead time of %f seconds, with a desired "
+ "decoded buffer length of %f.",
+ 1.0 * lead_time * 1E-9, config.audio_decoded_buffer_desired_length);
+ very_early_packets_signalled = 1;
+ }
+ usleep(((1000000 * conn->frames_per_packet) / conn->input_rate) *
+ 2); // wait for approximately the length of two packets
}
- new_audio_block_needed = 1; // the block has been used up and is no longer current
} else {
- if ((have_valid_time != 0) && (very_early_packets_signalled == 0) &&
- (lead_time * 1E-9 > (config.audio_decoded_buffer_desired_length + 0.2))) {
- debug(1,
- "incoming frame suddenly (?) has a lead time of %f seconds, with a desired "
- "decoded buffer length of %f.",
- 1.0 * lead_time * 1E-9, config.audio_decoded_buffer_desired_length);
- very_early_packets_signalled = 1;
- }
- usleep(((1000000 * conn->frames_per_packet) / conn->input_rate) *
- 2); // wait for approximately the length of two packets
+ debug(3, "just you wait, Henry Higgins, without valid timing information...");
+ usleep(20000); // just you wait, Henry Higgins...
}
}
}
projects / thirdparty / shairport-sync.git / commitdiff
