WHIP: Refine code.

libavformat/rtcenc.c

@@ -73,58 +73,58 @@
 typedef struct RTCContext {
     AVClass *av_class;
 
-    /* input audio and video codec parameters */
+    /* Input audio and video codec parameters */
     AVCodecParameters *audio_par;
     AVCodecParameters *video_par;
 
-    /* the ICE username and pwd fragment generated by the muxer. */
+    /* The ICE username and pwd fragment generated by the muxer. */
     char ice_ufrag_local[9];
     char ice_pwd_local[33];
-    /* the SSRC of the audio and video stream, generated by the muxer. */
+    /* The SSRC of the audio and video stream, generated by the muxer. */
     uint32_t audio_ssrc;
     uint32_t video_ssrc;
-    /* the PT(Payload Type) of stream, generated by the muxer. */
+    /* The PT(Payload Type) of stream, generated by the muxer. */
     uint8_t audio_payload_type;
     uint8_t video_payload_type;
     /**
-     * the SDP offer generated by the muxer according to the codec parameters,
+     * The SDP offer generated by the muxer according to the codec parameters,
      * DTLS and ICE information.
      * */
     char *sdp_offer;
 
-    /* the ICE username and pwd from remote server. */
+    /* The ICE username and pwd from remote server. */
     char *ice_ufrag_remote;
     char *ice_pwd_remote;
     /**
-     * the ICE candidate protocol, priority, host and port. Note that only
+     * The ICE candidate protocol, priority, host and port. Note that only
      * support one candidate for now. We will choose the first udp candidate.
      * We will support multiple candidates in the future.
      */
     char *ice_protocol;
     char *ice_host;
     int ice_port;
-    /* the SDP answer received from the WebRTC server. */
+    /* The SDP answer received from the WebRTC server. */
     char *sdp_answer;
 
-    /* whether the timer should be reset. */
+    /* Whether the timer should be reset. */
     int dtls_should_reset_timer;
-    /* whether the DTLS is done at least for us. */
+    /* Whether the DTLS is done at least for us. */
     int dtls_done_for_us;
-    /* the number of packets retransmitted for DTLS. */
+    /* The number of packets retransmitted for DTLS. */
     int dtls_arq_packets;
     /**
-     * the material to build SRTP master key, generated by DTLS, the layout is:
+     * The material to build SRTP master key, generated by DTLS, the layout is:
      *          16B         16B         14B             14B
      *      client_key | server_key | client_salt | server_salt
      */
     uint8_t dtls_srtp_material[DTLS_SRTP_MASTER_KEY_LEN * 2];
 
-    /* the SRTP send context, to encrypt outgoing packets. */
+    /* The SRTP send context, to encrypt outgoing packets. */
     struct SRTPContext srtp_send;
-    /* the SRTP receive context, to decrypt incoming packets. */
+    /* The SRTP receive context, to decrypt incoming packets. */
     struct SRTPContext srtp_recv;
 
-    /* the UDP transport is used for delivering ICE, DTLS and SRTP packets. */
+    /* The UDP transport is used for delivering ICE, DTLS and SRTP packets. */
     URLContext *udp_uc;
 } RTCContext;
 
@@ -388,7 +388,7 @@ static int exchange_sdp(AVFormatContext *s)
     int ret;
     char buf[MAX_URL_SIZE];
     RTCContext *rtc = s->priv_data;
-    /* the URL context is an HTTP transport layer for the WHIP protocol. */
+    /* The URL context is an HTTP transport layer for the WHIP protocol. */
     URLContext *whip_uc = NULL;
 
     char *tmp = av_mallocz(MAX_SDP_SIZE);
@@ -419,7 +419,7 @@ static int exchange_sdp(AVFormatContext *s)
     while (1) {
         ret = ffurl_read(whip_uc, buf, sizeof(buf));
         if (ret == AVERROR_EOF) {
-            /* reset the error because we read all response as answer util EOF. */
+            /* Reset the error because we read all response as answer util EOF. */
             ret = 0;
             break;
         }
@@ -537,15 +537,15 @@ static int ice_create_request(AVFormatContext *s, uint8_t *buf, int size_of_buf,
         goto end;
     }
 
-    /* write 20 bytes header */
+    /* Write 20 bytes header */
     avio_wb16(pb, 0x0001); /* STUN binding request */
     avio_wb16(pb, 0);      /* length */
     avio_wb32(pb, 0x2112A442); /* magic cookie */
     avio_wb32(pb, av_get_random_seed()); /* transaction ID */
     avio_wb32(pb, av_get_random_seed()); /* transaction ID */
     avio_wb32(pb, av_get_random_seed()); /* transaction ID */
 
-    /* the username is the concatenation of the two ICE ufrag */
+    /* The username is the concatenation of the two ICE ufrag */
     ret = snprintf(username, sizeof(username), "%s:%s", rtc->ice_ufrag_remote, rtc->ice_ufrag_local);
     if (ret <= 0 || ret >= sizeof(username)) {
         av_log(s, AV_LOG_ERROR, "Failed to build username %s:%s, max=%lu, ret=%d\n",
@@ -554,13 +554,13 @@ static int ice_create_request(AVFormatContext *s, uint8_t *buf, int size_of_buf,
         goto end;
     }
 
-    /* write the username attribute */
+    /* Write the username attribute */
     avio_wb16(pb, 0x0006); /* attribute type username */
     avio_wb16(pb, ret); /* size of username */
     avio_write(pb, username, ret); /* bytes of username */
     ffio_fill(pb, 0, (4 - (ret % 4)) % 4); /* padding */
 
-    /* build and update message integrity */
+    /* Build and update message integrity */
     avio_wb16(pb, 0x0008); /* attribute type message integrity */
     avio_wb16(pb, 20); /* size of message integrity */
     ffio_fill(pb, 0, 20); /* fill with zero to directly write and skip it */
@@ -571,14 +571,14 @@ static int ice_create_request(AVFormatContext *s, uint8_t *buf, int size_of_buf,
     av_hmac_update(hmac, buf, size - 24);
     av_hmac_final(hmac, buf + size - 20, 20);
 
-    /* write the fingerprint attribute */
+    /* Write the fingerprint attribute */
     avio_wb16(pb, 0x8028); /* attribute type fingerprint */
     avio_wb16(pb, 4); /* size of fingerprint */
     ffio_fill(pb, 0, 4); /* fill with zero to directly write and skip it */
     size = avio_tell(pb);
     buf[2] = (size - 20) >> 8;
     buf[3] = (size - 20) & 0xFF;
-    /* refer to the av_hash_alloc("CRC32"), av_hash_init and av_hash_final */
+    /* Refer to the av_hash_alloc("CRC32"), av_hash_init and av_hash_final */
     crc32 = av_crc(av_crc_get_table(AV_CRC_32_IEEE_LE), 0xFFFFFFFF, buf, size - 8) ^ 0xFFFFFFFF;
     avio_skip(pb, -4);
     avio_wb32(pb, crc32 ^ 0x5354554E); /* xor with "STUN" */
@@ -620,33 +620,33 @@ static int ice_handshake(AVFormatContext *s)
         goto end;
     }
 
-    /* make the socket non-blocking, set to READ and WRITE mode after connected */
+    /* Make the socket non-blocking, set to READ and WRITE mode after connected */
     ff_socket_nonblock(ffurl_get_file_handle(rtc->udp_uc), 1);
     rtc->udp_uc->flags |= AVIO_FLAG_READ | AVIO_FLAG_NONBLOCK;
 
-    /* build the STUN binding request. */
+    /* Build the STUN binding request. */
     ret = ice_create_request(s, buf, sizeof(buf), &size);
     if (ret < 0) {
         av_log(s, AV_LOG_ERROR, "Failed to create STUN binding request, size=%d\n", size);
         goto end;
     }
 
-    /* fast retransmit the STUN binding request. */
+    /* Fast retransmit the STUN binding request. */
     do {
         ret = ffurl_write(rtc->udp_uc, buf, size);
         if (ret < 0) {
             av_log(s, AV_LOG_ERROR, "Failed to send STUN binding request, size=%d\n", size);
             goto end;
         }
 
-        /* if max retries is 6 and start timeout is 21ms, the total timeout
+        /* If max retries is 6 and start timeout is 21ms, the total timeout
          * is about 21 + 42 + 84 + 168 + 336 + 672 = 1263ms. */
         if (fast_retries) {
             av_usleep(timeout * 1000);
             timeout *= 2;
         }
 
-        /* read the STUN binding response. */
+        /* Read the STUN binding response. */
         ret = ffurl_read(rtc->udp_uc, buf, sizeof(buf));
         if (ret < 0) {
             if (ret == AVERROR(EAGAIN) && fast_retries) {
@@ -730,10 +730,10 @@ static unsigned int openssl_dtls_timer_cb(SSL *dtls, unsigned int previous_us)
     AVFormatContext *s = (AVFormatContext*)SSL_get_ex_data(dtls, 0);
     RTCContext *rtc = s->priv_data;
 
-    /* double the timeout, note that it may be 0. */
+    /* Double the timeout, note that it may be 0. */
     unsigned int timeout_us = previous_us * 2;
 
-    /* if previous_us is 0, for example, the HelloVerifyRequest, we should respond it ASAP.
+    /* If previous_us is 0, for example, the HelloVerifyRequest, we should respond it ASAP.
      * when got ServerHello, we should reset the timer. */
     if (!previous_us || rtc->dtls_should_reset_timer) {
         timeout_us =  50 * 1000; /* in us */
@@ -755,7 +755,7 @@ static void openssl_state_trace(AVFormatContext *s, uint8_t *data, int length, i
     uint8_t handshake_type = 0;
     RTCContext *rtc = s->priv_data;
 
-    /* change_cipher_spec(20), alert(21), handshake(22), application_data(23) */
+    /* Change_cipher_spec(20), alert(21), handshake(22), application_data(23) */
     if (length >= 1) {
         content_type = (uint8_t)data[0];
     }
@@ -784,7 +784,7 @@ static void openssl_state_trace(AVFormatContext *s, uint8_t *data, int length, i
  */
 static int openssl_verify_callback(int preverify_ok, X509_STORE_CTX *ctx)
 {
-    /* always OK, we don't check the certificate of client, because we allow client self-sign certificate. */
+    /* Always OK, we don't check the certificate of client, because we allow client self-sign certificate. */
     return 1;
 }
 
@@ -797,7 +797,7 @@ static av_cold int openssl_init_dtls(AVFormatContext *s, SSL *dtls, SSL_CTX *dtl
 {
     int ret;
 
-    /* should use the curves in ClientHello.supported_groups, for example:
+    /* Should use the curves in ClientHello.supported_groups, for example:
      *      Supported Group: x25519 (0x001d)
      *      Supported Group: secp256r1 (0x0017)
      *      Supported Group: secp384r1 (0x0018)
@@ -821,42 +821,42 @@ static av_cold int openssl_init_dtls(AVFormatContext *s, SSL *dtls, SSL_CTX *dtl
         goto end;
     }
 
-    /* for ECDSA, we could set the curves list. */
+    /* For ECDSA, we could set the curves list. */
     SSL_CTX_set1_curves_list(dtls_ctx, "P-521:P-384:P-256");
 
-    /* we use "ALL", while you can use "DEFAULT" means "ALL:!EXPORT:!LOW:!aNULL:!eNULL:!SSLv2" */
+    /* We use "ALL", while you can use "DEFAULT" means "ALL:!EXPORT:!LOW:!aNULL:!eNULL:!SSLv2" */
     if (SSL_CTX_set_cipher_list(dtls_ctx, DTLS_CIPHER_SUTES) != 1) {
         av_log(s, AV_LOG_ERROR, "DTLS: SSL_CTX_set_cipher_list failed\n");
         ret = AVERROR(EINVAL);
         goto end;
     }
-    /* server will send Certificate Request. */
+    /* Server will send Certificate Request. */
     SSL_CTX_set_verify(dtls_ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, openssl_verify_callback);
-    /* the depth count is "level 0:peer certificate", "level 1: CA certificate",
+    /* The depth count is "level 0:peer certificate", "level 1: CA certificate",
      * "level 2: higher level CA certificate", and so on. */
     SSL_CTX_set_verify_depth(dtls_ctx, 4);
-    /* whether we should read as many input bytes as possible (for non-blocking reads) or not. */
+    /* Whether we should read as many input bytes as possible (for non-blocking reads) or not. */
     SSL_CTX_set_read_ahead(dtls_ctx, 1);
-    /* only support SRTP_AES128_CM_SHA1_80, please read ssl/d1_srtp.c */
+    /* Only support SRTP_AES128_CM_SHA1_80, please read ssl/d1_srtp.c */
     ret = SSL_CTX_set_tlsext_use_srtp(dtls_ctx, "SRTP_AES128_CM_SHA1_80");
     if (ret) {
         av_log(s, AV_LOG_ERROR, "DTLS: SSL_CTX_set_tlsext_use_srtp failed, ret=%d\n", ret);
         ret = AVERROR(EINVAL);
         goto end;
     }
 
-    /* setup the callback for logging. */
+    /* Setup the callback for logging. */
     SSL_set_ex_data(dtls, 0, s);
     SSL_set_info_callback(dtls, openssl_on_info);
 
-    /* set dtls fragment size */
+    /* Set dtls fragment size */
     SSL_set_options(dtls, SSL_OP_NO_QUERY_MTU);
     SSL_set_mtu(dtls, DTLS_FRAGMENT_MAX_SIZE);
 
-    /* set the callback for ARQ timer. */
+    /* Set the callback for ARQ timer. */
     DTLS_set_timer_cb(dtls, openssl_dtls_timer_cb);
 
-    /* setup DTLS as active, which is client role. */
+    /* Setup DTLS as active, which is client role. */
     SSL_set_connect_state(dtls);
     SSL_set_max_send_fragment(dtls, DTLS_FRAGMENT_MAX_SIZE);
 
@@ -872,23 +872,23 @@ static int openssl_drive_context(AVFormatContext *s, SSL *dtls, BIO *bio_in, BIO
     char buf[MAX_UDP_SIZE];
     RTCContext *rtc = s->priv_data;
 
-    /* drive the SSL context by state change, arq or response messages. */
+    /* Drive the SSL context by state change, arq or response messages. */
     r0 = SSL_do_handshake(dtls);
     r1 = SSL_get_error(dtls, r0);
 
-    /* handshake successfully done */
+    /* Handshake successfully done */
     if (r0 == 1) {
         rtc->dtls_done_for_us = 1;
         return 0;
     }
 
-    /* handshake failed with fatal error */
+    /* Handshake failed with fatal error */
     if (r0 < 0 && r1 != SSL_ERROR_WANT_READ) {
         av_log(s, AV_LOG_ERROR, "DTLS: Start handshake failed, loop=%d, r0=%d, r1=%d\n", loop, r0, r1);
         return AVERROR(EIO);
     }
 
-    /* fast retransmit the request util got response. */
+    /* Fast retransmit the request util got response. */
     for (i = 0; i < UDP_FAST_RETRIES && !res_size; i++) {
         req_size = BIO_get_mem_data(bio_out, (char**)&data);
         openssl_state_trace(s, data, req_size, 0, r0, r1);
@@ -904,14 +904,14 @@ static int openssl_drive_context(AVFormatContext *s, SSL *dtls, BIO *bio_in, BIO
 
         for (j = 0; j < UDP_FAST_RETRIES && !res_size; j++) {
             ret = ffurl_read(rtc->udp_uc, buf, sizeof(buf));
-            /* got response successfully. */
+            /* Got response successfully. */
             if (ret > 0) {
                 res_size = ret;
                 rtc->dtls_should_reset_timer = 1;
                 break;
             }
 
-            /* fatal error or timeout. */
+            /* Fatal error or timeout. */
             if (ret != AVERROR(EAGAIN)) {
                 av_log(s, AV_LOG_ERROR, "DTLS: Read response failed, loop=%d, content=%d, handshake=%d\n",
                     loop, req_ct, req_ht);
@@ -939,7 +939,7 @@ static int openssl_drive_context(AVFormatContext *s, SSL *dtls, BIO *bio_in, BIO
         }
     }
 
-    /* trace the response packet, feed to SSL. */
+    /* Trace the response packet, feed to SSL. */
     BIO_reset(bio_in);
     openssl_state_trace(s, buf, res_size, 1, r0, SSL_ERROR_NONE);
     res_ct = res_size > 0 ? buf[0]: 0;
@@ -969,7 +969,7 @@ static int openssl_dtls_handshake(AVFormatContext *s)
     const char* dst = "EXTRACTOR-dtls_srtp";
     RTCContext *rtc = s->priv_data;
 
-    /* create and initialize SSL context. */
+    /* Create and initialize SSL context. */
     dtls_pkey = EVP_PKEY_new();
     eckey = EC_KEY_new();
 
@@ -999,7 +999,7 @@ static int openssl_dtls_handshake(AVFormatContext *s)
         goto end;
     }
 
-    /* export SRTP master key after DTLS done */
+    /* Export SRTP master key after DTLS done */
     ret = SSL_export_keying_material(dtls, rtc->dtls_srtp_material, sizeof(rtc->dtls_srtp_material),
         dst, strlen(dst), NULL, 0, 0);
     if (!ret) {
@@ -1035,15 +1035,15 @@ static int setup_srtp(AVFormatContext *s)
     const char* suite = "AES_CM_128_HMAC_SHA1_80";
     RTCContext *rtc = s->priv_data;
 
-    /* as DTLS client, the send key is client master key plus salt. */
+    /* As DTLS client, the send key is client master key plus salt. */
     memcpy(send_key, rtc->dtls_srtp_material, 16);
     memcpy(send_key + 16, rtc->dtls_srtp_material + 32, 14);
 
-    /* as DTLS client, the recv key is server master key plus salt. */
+    /* As DTLS client, the recv key is server master key plus salt. */
     memcpy(recv_key, rtc->dtls_srtp_material + 16, 16);
     memcpy(recv_key + 16, rtc->dtls_srtp_material + 46, 14);
 
-    /* setup SRTP context for outgoing packets */
+    /* Setup SRTP context for outgoing packets */
     if (!av_base64_encode(buf, sizeof(buf), send_key, sizeof(send_key))) {
         av_log(s, AV_LOG_ERROR, "Failed to encode send key\n");
         ret = AVERROR(EIO);
@@ -1056,7 +1056,7 @@ static int setup_srtp(AVFormatContext *s)
         goto end;
     }
 
-    /* setup SRTP context for incoming packets */
+    /* Setup SRTP context for incoming packets */
     if (!av_base64_encode(buf, sizeof(buf), recv_key, sizeof(recv_key))) {
         av_log(s, AV_LOG_ERROR, "Failed to encode recv key\n");
         ret = AVERROR(EIO);