get samples_per_frame from hdr_frame_samples

Signed-off-by: zhangtl <tongliangzhang@bestechnic.com>

minimp3.h

@@ -12,7 +12,7 @@
 
 typedef struct
 {
-    int frame_bytes, frame_offset, channels, hz, layer, bitrate_kbps;
+    int frame_bytes, frame_offset, channels, hz, layer, bitrate_kbps, samples_per_frame;
 } mp3dec_frame_info_t;
 
 typedef struct
@@ -890,13 +890,6 @@ static void L3_midside_stereo(float *left, int n)
             VSTORE(left + i, VADD(vl, vr));
             VSTORE(right + i, VSUB(vl, vr));
         }
-#ifdef __GNUC__
-        /* Workaround for spurious -Waggressive-loop-optimizations warning from gcc.
-         * For more info see: https://github.com/lieff/minimp3/issues/88
-         */
-        if (__builtin_constant_p(n % 4 == 0) && n % 4 == 0)
-            return;
-#endif
     }
 #endif /* HAVE_SIMD */
     for (; i < n; i++)

minimp3_ex.h

@@ -503,8 +503,6 @@ int mp3dec_iterate_buf(const uint8_t *buf, size_t buf_size, MP3D_ITERATE_CB call
         return MP3D_E_PARAM;
     /* skip id3 */
     mp3dec_skip_id3(&buf, &buf_size);
-    if (!buf_size)
-        return 0;
     mp3dec_frame_info_t frame_info;
     memset(&frame_info, 0, sizeof(frame_info));
     do
@@ -523,11 +521,13 @@ int mp3dec_iterate_buf(const uint8_t *buf, size_t buf_size, MP3D_ITERATE_CB call
         frame_info.layer = 4 - HDR_GET_LAYER(hdr);
         frame_info.bitrate_kbps = hdr_bitrate_kbps(hdr);
         frame_info.frame_bytes = frame_size;
+        frame_info.samples_per_frame = hdr_frame_samples(hdr);
 
         if (callback)
         {
-            if ((ret = callback(user_data, hdr, frame_size, free_format_bytes, buf_size, hdr - orig_buf, &frame_info)))
+            if ((ret = callback(user_data, hdr, frame_size, free_format_bytes, buf_size, hdr - orig_buf, &frame_info))){
                 return ret;
+            }
         }
         buf      += frame_size;
         buf_size -= frame_size;