faster code for fixing truncated samples

kirkryan · Apr 24, 2019 · f156c4b · f156c4b
1 parent 44c8d8b
commit f156c4b
Show file tree

Hide file tree

Showing 2 changed files with 4 additions and 10 deletions.
diff --git a/GPMF_writer.c b/GPMF_writer.c
@@ -2614,18 +2614,12 @@ uint32_t GPMFWriteGetPayloadAndSession(	size_t ws_handle, uint32_t channel, uint
 
 									if (dm->sampleCount[ts_pos] > 1) // multiple sample stored with one timestamp, interpolate
 									{
-										uint32_t additionSmps = 0, sampleTSdelta = (dm->deltaTimeStamp[ts_pos]<<8) / dm->sampleCount[ts_pos];
-										uint64_t refineTS = next_first_ts << 8; // improved precision.
+										uint32_t additionSmps;
 
-										while (((refineTS + sampleTSdelta)>>8) < latestTimeStamp)
-										{
-											refineTS += sampleTSdelta;
-											additionSmps++;
-										}
-										dm->deltaTimeStamp[ts_pos] -= (refineTS >> 8) - next_first_ts;
+										additionSmps = dm->sampleCount[ts_pos] * (latestTimeStamp - next_first_ts) / dm->deltaTimeStamp[ts_pos];
+										dm->deltaTimeStamp[ts_pos] -= additionSmps * dm->deltaTimeStamp[ts_pos] / dm->sampleCount[ts_pos];
 										dm->sampleCount[ts_pos] -= additionSmps;
 
-										next_first_ts = refineTS >> 8;
 										smps += additionSmps;
 									}
 

diff --git a/demo/GPMF_demo.c b/demo/GPMF_demo.c
@@ -481,7 +481,7 @@ int main(int argc, char *argv[])
 			}
 
 			if(faketime == 0)
-				GPMFWriteGetPayloadWindow(gpmfhandle, GPMF_CHANNEL_TIMED, (uint32_t *)buffer, sizeof(buffer), &payload, &payload_size, 250); // Flush partial second
+				GPMFWriteGetPayloadWindow(gpmfhandle, GPMF_CHANNEL_TIMED, (uint32_t *)buffer, sizeof(buffer), &payload, &payload_size, 299); // Flush partial second
 
 			nowtick = payloadtick + (tick - payloadtick) * 8 / 10; // test by reading out only the last half samples
 			nowtick = tick+1; // test by reading out only the last half samples