From 776244b79a8bcfb5732f39fbebb9cd7fc0092bcb Mon Sep 17 00:00:00 2001 From: erankor Date: Tue, 29 May 2018 17:29:09 +0300 Subject: [PATCH 2/2] qt-faststart - optimize the offset change loop --- tools/qt-faststart.c | 42 +++++++++++++++++++++++++----------------- 1 file changed, 25 insertions(+), 17 deletions(-) diff --git a/tools/qt-faststart.c b/tools/qt-faststart.c index d0ae7245f3..2ddaf87e1b 100644 --- a/tools/qt-faststart.c +++ b/tools/qt-faststart.c @@ -96,9 +96,11 @@ int main(int argc, char *argv[]) int64_t last_offset; unsigned char *moov_atom = NULL; unsigned char *ftyp_atom = NULL; + unsigned char *ptr; + unsigned char *end; uint64_t moov_atom_size; uint64_t ftyp_atom_size = 0; - uint64_t i, j; + uint64_t i; uint32_t offset_count; uint64_t current_offset; int64_t start_offset = 0; @@ -253,13 +255,16 @@ int main(int argc, char *argv[]) printf(" bad atom size/element count\n"); goto error_out; } - for (j = 0; j < offset_count; j++) { - current_offset = BE_32(&moov_atom[i + 12 + j * 4]); + + ptr = moov_atom + i + 12; + end = ptr + offset_count * 4; + while (ptr < end) { + current_offset = BE_32(ptr); current_offset += moov_atom_size; - moov_atom[i + 12 + j * 4 + 0] = (current_offset >> 24) & 0xFF; - moov_atom[i + 12 + j * 4 + 1] = (current_offset >> 16) & 0xFF; - moov_atom[i + 12 + j * 4 + 2] = (current_offset >> 8) & 0xFF; - moov_atom[i + 12 + j * 4 + 3] = (current_offset >> 0) & 0xFF; + *ptr++ = (current_offset >> 24) & 0xFF; + *ptr++ = (current_offset >> 16) & 0xFF; + *ptr++ = (current_offset >> 8) & 0xFF; + *ptr++ = (current_offset >> 0) & 0xFF; } i += atom_size - 4; } else if (atom_type == CO64_ATOM) { @@ -274,17 +279,20 @@ int main(int argc, char *argv[]) printf(" bad atom size/element count\n"); goto error_out; } - for (j = 0; j < offset_count; j++) { - current_offset = BE_64(&moov_atom[i + 12 + j * 8]); + + ptr = moov_atom + i + 12; + end = ptr + offset_count * 8; + while (ptr < end) { + current_offset = BE_64(ptr); current_offset += moov_atom_size; - moov_atom[i + 12 + j * 8 + 0] = (current_offset >> 56) & 0xFF; - moov_atom[i + 12 + j * 8 + 1] = (current_offset >> 48) & 0xFF; - moov_atom[i + 12 + j * 8 + 2] = (current_offset >> 40) & 0xFF; - moov_atom[i + 12 + j * 8 + 3] = (current_offset >> 32) & 0xFF; - moov_atom[i + 12 + j * 8 + 4] = (current_offset >> 24) & 0xFF; - moov_atom[i + 12 + j * 8 + 5] = (current_offset >> 16) & 0xFF; - moov_atom[i + 12 + j * 8 + 6] = (current_offset >> 8) & 0xFF; - moov_atom[i + 12 + j * 8 + 7] = (current_offset >> 0) & 0xFF; + *ptr++ = (current_offset >> 56) & 0xFF; + *ptr++ = (current_offset >> 48) & 0xFF; + *ptr++ = (current_offset >> 40) & 0xFF; + *ptr++ = (current_offset >> 32) & 0xFF; + *ptr++ = (current_offset >> 24) & 0xFF; + *ptr++ = (current_offset >> 16) & 0xFF; + *ptr++ = (current_offset >> 8) & 0xFF; + *ptr++ = (current_offset >> 0) & 0xFF; } i += atom_size - 4; } -- 2.16.2.windows.1