diff --git a/src/mp4/moof.c b/src/mp4/moof.c
index ede03a6..8f7ba6e 100644
--- a/src/mp4/moof.c
+++ b/src/mp4/moof.c
@@ -175,11 +175,11 @@ enum BufError write_tfhd(
     uint64_t flags = 0x0;
     const bool base_data_offset_present = false;
     const bool sample_description_index_present = false;
-    const bool default_sample_duration_present = true;
+    const bool default_sample_duration_present = false;
     const bool default_sample_size_present = true;
     const bool default_sample_flags_present = true;
     const bool duration_is_empty = false;
-    const bool default_base_is_moof = false;
+    const bool default_base_is_moof = true;
 
     if (base_data_offset_present) {
         flags = flags | 0x000001;
@@ -278,10 +278,9 @@ enum BufError write_trun(
     err = put_u8(ptr, 0);
     chk_err; // 1 version
     bool data_offset_present = true;
-    bool first_sample_flags_present = false;
-    bool sample_duration_present = !is_audio;
-    bool sample_size_present = !is_audio;
-    bool sample_flags_present = !is_audio;
+    bool first_sample_flags_present = true;
+    bool sample_duration_present = true;
+    bool sample_size_present = true;
     {
         uint64_t flags = 0x0;
         if (data_offset_present) {
@@ -296,9 +295,6 @@ enum BufError write_trun(
         if (sample_size_present) {
             flags = flags | 0x000200;
         } // 0x000200 sample-size-present
-        if (sample_flags_present) {
-            flags = flags | 0x000400;
-        } // 0x000400 sample-flags-present
         err = put_u8(ptr, flags >> 16);
         chk_err;
         
@@ -334,10 +330,6 @@ enum BufError write_trun(
             err = put_u32_be(ptr, sample_info.size);
             chk_err; // 4 sample_size
         }
-        if (sample_flags_present) {
-            err = put_u32_be(ptr, sample_info.flags);
-            chk_err; // 4 sample_flags
-        }
     }
 
     err = put_u32_be_to_offset(ptr, start_atom, ptr->offset - start_atom);
diff --git a/src/mp4/mp4.c b/src/mp4/mp4.c
index e38bb3c..28b2cfe 100644
--- a/src/mp4/mp4.c
+++ b/src/mp4/mp4.c
@@ -99,17 +99,19 @@ enum BufError mp4_set_slice(const char *nal_data, const uint32_t nal_len,
     char is_iframe) {
     enum BufError err;
 
-    struct SampleInfo samples_info[9];
+    struct SampleInfo samples_info[2];
     memset(samples_info, 0, sizeof(samples_info));
     samples_info[0].size = nal_len + 4; // add size of sample
     samples_info[0].duration = default_sample_size;
     samples_info[0].flags = is_iframe ? 0 : 65536;
     samples_info[1].size = buf_aud.offset;
+    samples_info[1].duration = default_sample_size * 
+        buf_aud.offset / (aud_bitrate * 25 / 6.f);
 
     buf_moof.offset = 0;
     err = write_moof(
         &buf_moof, 0, 0, 0, default_sample_size, samples_info,
-        1, samples_info + 1, buf_aud.offset / aud_framesize);
+        1, samples_info + 1, 1);
     chk_err;
 
     buf_mdat.offset = 0;