rtp: h264: Move STAP-A NAL parsing to a function

libavformat/rtpdec_h264.c

@@ -180,49 +180,13 @@ static int sdp_parse_fmtp_config_h264(AVFormatContext *s,
     return 0;
 }
 
-// return 0 on packet, no more left, 1 on packet, 1 on partial packet
-static int h264_handle_packet(AVFormatContext *ctx, PayloadContext *data,
-                              AVStream *st, AVPacket *pkt, uint32_t *timestamp,
-                              const uint8_t *buf, int len, uint16_t seq,
-                              int flags)
+static int h264_handle_packet_stap_a(AVFormatContext *ctx, AVPacket *pkt,
+                                     const uint8_t *buf, int len)
 {
-    uint8_t nal;
-    uint8_t type;
-    int result = 0;
-
-    if (!len) {
-        av_log(ctx, AV_LOG_ERROR, "Empty H264 RTP packet\n");
-        return AVERROR_INVALIDDATA;
-    }
-    nal  = buf[0];
-    type = nal & 0x1f;
-
-    assert(data);
-    assert(buf);
-
-    /* Simplify the case (these are all the nal types used internally by
-     * the h264 codec). */
-    if (type >= 1 && type <= 23)
-        type = 1;
-    switch (type) {
-    case 0:                    // undefined, but pass them through
-    case 1:
-        if ((result = av_new_packet(pkt, len + sizeof(start_sequence))) < 0)
-            return result;
-        memcpy(pkt->data, start_sequence, sizeof(start_sequence));
-        memcpy(pkt->data + sizeof(start_sequence), buf, len);
-        COUNT_NAL_TYPE(data, nal);
-        break;
-
-    case 24:                   // STAP-A (one packet, multiple nals)
-        // consume the STAP-A NAL
-        buf++;
-        len--;
-        // first we are going to figure out the total size
-        {
     int pass         = 0;
     int total_length = 0;
     uint8_t *dst     = NULL;
+    int ret;
 
     for (pass = 0; pass < 2; pass++) {
         const uint8_t *src = buf;
@@ -265,14 +229,57 @@ static int h264_handle_packet(AVFormatContext *ctx, PayloadContext *data,
         if (pass == 0) {
             /* now we know the total size of the packet (with the
              * start sequences added) */
-                    if ((result = av_new_packet(pkt, total_length)) < 0)
-                        return result;
+            if ((ret = av_new_packet(pkt, total_length)) < 0)
+                return ret;
             dst = pkt->data;
         } else {
             assert(dst - pkt->data == total_length);
         }
     }
+
+    return 0;
+}
+
+// return 0 on packet, no more left, 1 on packet, 1 on partial packet
+static int h264_handle_packet(AVFormatContext *ctx, PayloadContext *data,
+                              AVStream *st, AVPacket *pkt, uint32_t *timestamp,
+                              const uint8_t *buf, int len, uint16_t seq,
+                              int flags)
+{
+    uint8_t nal;
+    uint8_t type;
+    int result = 0;
+
+    if (!len) {
+        av_log(ctx, AV_LOG_ERROR, "Empty H264 RTP packet\n");
+        return AVERROR_INVALIDDATA;
     }
+    nal  = buf[0];
+    type = nal & 0x1f;
+
+    assert(data);
+    assert(buf);
+
+    /* Simplify the case (these are all the nal types used internally by
+     * the h264 codec). */
+    if (type >= 1 && type <= 23)
+        type = 1;
+    switch (type) {
+    case 0:                    // undefined, but pass them through
+    case 1:
+        if ((result = av_new_packet(pkt, len + sizeof(start_sequence))) < 0)
+            return result;
+        memcpy(pkt->data, start_sequence, sizeof(start_sequence));
+        memcpy(pkt->data + sizeof(start_sequence), buf, len);
+        COUNT_NAL_TYPE(data, nal);
+        break;
+
+    case 24:                   // STAP-A (one packet, multiple nals)
+        // consume the STAP-A NAL
+        buf++;
+        len--;
+        // first we are going to figure out the total size
+        result = h264_handle_packet_stap_a(ctx, pkt, buf, len);
         break;
 
     case 25:                   // STAP-B