FS-8243: Improve the way FEC info is detected within frames (added support for ptimes...

(Claude Lamblin)

diff --git a/src/mod/codecs/mod_opus/mod_opus.c b/src/mod/codecs/mod_opus/mod_opus.c
index 159a50c22b6fe28720f8e4dbe0c1210926c1946d..e515a16c534b1c1ba37cef459ec4d25a831f20cc 100644 (file)
--- a/src/mod/codecs/mod_opus/mod_opus.c
+++ b/src/mod/codecs/mod_opus/mod_opus.c
@@ -271,39 +271,45 @@ static char *gen_fmtp(opus_codec_settings_t *settings, switch_memory_pool_t *poo
 
 static switch_bool_t switch_opus_has_fec(const uint8_t* payload,int payload_length_bytes) 
 {
-       int frames, payload_length_ms;
-       int n;
+       int nb_silk_frames, nb_opus_frames, n, i; 
        opus_int16 frame_sizes[48];
        const unsigned char *frame_data[48];
 
-       if (payload == NULL || payload_length_bytes <= 0){
-               switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "corrupted packet\n");
+       if (payload == NULL || payload_length_bytes <= 0) {
+               switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "corrupted packet (invalid size)\n");
                return SWITCH_FALSE;
        }
-
-       if (payload[0] & 0x80){   
+       if (payload[0] & 0x80) {   
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "FEC in CELT_ONLY mode ?!\n");
                return SWITCH_FALSE;
        }
-       
-       payload_length_ms = opus_packet_get_samples_per_frame(payload, 48000) / 48;
-       if (10 > payload_length_ms) {
-                       payload_length_ms = 10;
-       }
-       
-       frames = opus_packet_parse(payload, payload_length_bytes, NULL, frame_data, frame_sizes, NULL);
-       
-       if (frames < 0) {
-               return SWITCH_FALSE;
-       }
-       
-       if (frame_sizes[0] <= 1) {
+                       
+       if ((nb_opus_frames = opus_packet_parse(payload, payload_length_bytes, NULL, frame_data, frame_sizes, NULL)) < 0 ) {
+               switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "OPUS_INVALID_PACKET ! nb_opus_frames: %d\n", nb_opus_frames);
                return SWITCH_FALSE;
        }
-       
-       for (n = 0; n <= (payload[0]&0x4);n++) {
-               if (frame_data[0][0] & (0x80 >> ((n + 1) * (frames + 1) - 1))) {
-                       return SWITCH_TRUE; /*this works only for 20 ms frames now, it will return VAD for 40 ms or 60 ms*/
+
+       nb_silk_frames  = 0;
+
+       if ((payload[0] >> 3 ) < 12) { /* config in silk-only : NB,MB,WB */
+               nb_silk_frames = (payload[0] >> 3) & 0x3;
+               if(nb_silk_frames  == 0) {
+                       nb_silk_frames = 1;
+               }
+               if (nb_silk_frames == 1) {
+                       for (n = 0; n <= (payload[0]&0x4) ; n++) { /* mono or stereo */
+                               if (frame_data[0][0] & (0x80 >> ((n + 1) * (nb_silk_frames + 1) - 1))) {
+                                       return SWITCH_TRUE; /* 1st 20ms (or 10 ms) frame has FEC */                             
+                               }
+                       }
+               } else {
+                       opus_int16 LBRR_flag = 0 ;
+                       for (i=0 ; i < nb_opus_frames; i++ ) { /* only mono */
+                               LBRR_flag = (frame_data[i][0] >> (7 - nb_silk_frames)) & 0x1;
+                               if (LBRR_flag) {
+                                       return SWITCH_TRUE; /* one of the silk frames has FEC */ 
+                               }
+                       }
                }
        }
 
@@ -312,20 +318,26 @@ static switch_bool_t switch_opus_has_fec(const uint8_t* payload,int payload_leng
 
 static switch_status_t switch_opus_info(void * encoded_data, uint32_t len, uint32_t samples_per_second, char *print_text)
 {
-       int nb_samples;
-       int nb_frames;
+       /* nb_silk_frames: number of silk-frames (10 or 20 ms) in an opus frame:  0, 1, 2 or 3 */
+       /* computed from the 5 MSB (configuration) of the TOC byte (encoded_data[0]) */
+       /* nb_opus_frames: number of opus frames in the packet */
+       /* computed from the 2 LSB (p0p1) of the TOC byte */
+       /* p0p1 = 0  => nb_opus_frames= 1 */
+       /* p0p1 = 1 or 2  => nb_opus_frames= 2 */
+       /* p0p1 = 3  =>  given by the 6 LSB of  encoded_data[1] */
+
+       int nb_samples, nb_silk_frames, nb_opus_frames, n, i; 
        int audiobandwidth;
        const char *audiobandwidth_str = "UNKNOWN";
        opus_int16 frame_sizes[48];
        const unsigned char *frame_data[48];
        char has_fec = 0;
+       uint8_t * payload = encoded_data ;
 
        if (!encoded_data) {
                return SWITCH_STATUS_FALSE;
        }
 
-       nb_frames = opus_packet_get_nb_frames(encoded_data, len);
-       nb_samples = opus_packet_get_samples_per_frame(encoded_data, samples_per_second) * nb_frames;
        audiobandwidth = opus_packet_get_bandwidth(encoded_data);
 
        if (audiobandwidth == OPUS_BANDWIDTH_NARROWBAND) {
@@ -342,18 +354,41 @@ static switch_status_t switch_opus_info(void * encoded_data, uint32_t len, uint3
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "%s: OPUS_INVALID_PACKET !\n", print_text);
        }
 
-       if (opus_packet_parse(encoded_data, len, NULL, frame_data, frame_sizes, NULL)) {
-               if (frame_data[0]) {
-                       /*check only 1st frame*/
-                       has_fec = frame_data[0][0] & (0x80 >> 1);
+       if ((nb_opus_frames = opus_packet_parse(encoded_data, len, NULL, frame_data, frame_sizes, NULL)) < 0 ) {
+               switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "%s: OPUS_INVALID_PACKET ! frames: %d\n", print_text, nb_opus_frames);
+               return SWITCH_FALSE;
+       }
+
+       nb_samples = opus_packet_get_samples_per_frame(encoded_data, samples_per_second) * nb_opus_frames;
+       nb_silk_frames  = 0;
+
+       if ((payload[0] >> 3 ) < 12) { /* config in silk-only : NB,MB,WB */
+               nb_silk_frames = (payload[0] >> 3) & 0x3;
+               if(nb_silk_frames  == 0) {
+                       nb_silk_frames = 1;
+               }
+               if (nb_silk_frames == 1) { 
+                       for (n = 0; n <= (payload[0]&0x4) ; n++) { /* mono or stereo */
+                               if (frame_data[0][0] & (0x80 >> ((n + 1) * (nb_silk_frames + 1) - 1))){
+                                       has_fec = 1 ; /* 1st 20ms (or 10 ms) frame has fec */
+                               }
+                       }
+               } else {
+                       opus_int16 LBRR_flag = 0 ;
+                       for (i=0 ; i < nb_opus_frames; i++ ) { /* only mono */
+                               LBRR_flag = (frame_data[i][0] >> (7 - nb_silk_frames)) & 0x1;
+                               if (LBRR_flag) {
+                                       has_fec = 1;
+                               }
+                       }
                }
        }
 
-       switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "%s: frames [%d] samples [%d] audio bandwidth [%s] bytes [%d] FEC[%s]\n",
-                                         print_text, nb_frames, nb_samples, audiobandwidth_str, len, has_fec ? "yes" : "no");
+       switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "%s: nb_opus_frames [%d] nb_silk_frames [%d] samples [%d] audio bandwidth [%s] bytes [%d] FEC[%s]\n", 
+                                                       print_text, nb_opus_frames, nb_silk_frames, nb_samples, audiobandwidth_str, len, has_fec ? "yes" : "no" );
 
        return SWITCH_STATUS_SUCCESS;
-}
+} 
 
 static switch_status_t switch_opus_init(switch_codec_t *codec, switch_codec_flag_t flags, const switch_codec_settings_t *codec_settings)
 {