From f4d9148fe282879b9fcc755767c9c04de9ddbcfa Mon Sep 17 00:00:00 2001 From: Jan Ehrhardt Date: Sun, 30 Sep 2012 21:32:26 +0200 Subject: [PATCH] qt-faststart: speedup qt-faststart is terribly slow when the input file and the output file are on a slow disk like a SD card. By increasing the copy_buffer from 1K to 32M I decreased the processing time on a sample file from 1600 seconds to 4 seconds. The timing difference is during 'copying rest of file'. S:\SD_VIDEO\PRG001>e:\utils\qt-faststart 00005.mp4 5.mp4 ftyp 0 32 free 32 8 mdat 40 13744391 moov 13744431 141848 patching stco atom... patching stco atom... writing ftyp atom... writing moov atom... copying rest of file... Execution time: 1576.259 s S:\SD_VIDEO\PRG001>s:\utils\qt-faststart 00005.mp4 5.mp4 ftyp 0 32 free 32 8 mdat 40 13744391 moov 13744431 141848 patching stco atom... patching stco atom... writing ftyp atom... writing moov atom... copying rest of file... Execution time: 3.846 s Signed-off-by: Michael Niedermayer --- tools/qt-faststart.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/tools/qt-faststart.c b/tools/qt-faststart.c index ebbe95237c..bfa6f1a489 100644 --- a/tools/qt-faststart.c +++ b/tools/qt-faststart.c @@ -77,7 +77,7 @@ #define CO64_ATOM QT_ATOM('c', 'o', '6', '4') #define ATOM_PREAMBLE_SIZE 8 -#define COPY_BUFFER_SIZE 1024 +#define COPY_BUFFER_SIZE 33554432 int main(int argc, char *argv[]) { @@ -96,7 +96,7 @@ int main(int argc, char *argv[]) uint32_t offset_count; uint64_t current_offset; uint64_t start_offset = 0; - unsigned char copy_buffer[COPY_BUFFER_SIZE]; + unsigned char *copy_buffer = NULL; int bytes_to_copy; if (argc != 3) { @@ -293,6 +293,11 @@ int main(int argc, char *argv[]) } /* copy the remainder of the infile, from offset 0 -> last_offset - 1 */ + copy_buffer = malloc(COPY_BUFFER_SIZE); + if (!copy_buffer) { + printf("could not allocate %"PRIu64" bytes for copy_buffer\n", COPY_BUFFER_SIZE); + goto error_out; + } printf(" copying rest of file...\n"); while (last_offset) { if (last_offset > COPY_BUFFER_SIZE) @@ -315,6 +320,7 @@ int main(int argc, char *argv[]) fclose(outfile); free(moov_atom); free(ftyp_atom); + free(copy_buffer); return 0; @@ -325,5 +331,6 @@ error_out: fclose(outfile); free(moov_atom); free(ftyp_atom); + free(copy_buffer); return 1; }