[FFmpeg-user] Read Exif from file processed by FFMPEG

[Eugene Gekhter]

This might fall into the realm of extreme specificity, but I encountered a
very large discrepancy in performance when reading files generated by
FFMPEG and wanted to see if anybody had observed similar behavior in their
experience.

Situation:
Reading exif metadata from video files using exiftool for PHP.

Setup:
Version A: Original MTS file from camcorder (~ 2.5 minutes)
Version B: FFMPEG version of file (ffmpeg -i
/Volumes/16GB/PRIVATE/AVCHD/BDMV/STREAM/00013.MTS -c copy
~/Desktop/00013F.MTS)
Both versions are in same SSD folder (for unbiased performance readings)

Result: Time to read exif data from file (seconds):
Version A : 0.49976897239685
Version B: 17.803021192551

Here's the code I'm using for reading and timing:
$logger = new \Monolog\Logger('exiftool');

        $start = microtime(true);

        $reader = \PHPExiftool\Reader::create($logger);
        $file = "/Users/eugenegekhter/Desktop/00013.MTS";
        $metadatas = $reader->files($file)->first();

        foreach ($metadatas as $metadata)
        {
            var_dump($metadata);
        }

        $time_elapsed_us = microtime(true) - $start;

        var_dump($time_elapsed_us);

Here's ffprobe of original file:

ffprobe version N-64124-g84de3ed Copyright (c) 2007-2014 the FFmpeg
developers

  built on Jun 21 2014 17:13:02 with Apple LLVM version 5.1
(clang-503.0.40) (based on LLVM 3.4svn)

  configuration: --prefix=/Users/eugenegekhter/ffmpeg_build
--extra-cflags=-I/Users/eugenegekhter/ffmpeg_build/include
--extra-ldflags=-L/Users/eugenegekhter/ffmpeg_build/lib
--bindir=/Users/eugenegekhter/bin --extra-libs=-ldl --enable-gpl
--enable-libfdk-aac --enable-libx264 --enable-nonfree

  libavutil      52. 90.100 / 52. 90.100

  libavcodec     55. 68.100 / 55. 68.100

  libavformat    55. 44.100 / 55. 44.100

  libavdevice    55. 13.101 / 55. 13.101

  libavfilter     4.  9.100 /  4.  9.100

  libswscale      2.  6.100 /  2.  6.100

  libswresample   0. 19.100 /  0. 19.100

  libpostproc    52.  3.100 / 52.  3.100

Input #0, mpegts, from '/Users/eugenegekhter/Desktop/00013.MTS':

  Duration: 00:02:40.19, start: 0.382589, bitrate: 25334 kb/s

  Program 1

    Stream #0:0[0x1011]: Video: h264 (High) (HDMV / 0x564D4448), yuv420p,
1920x1080 [SAR 1:1 DAR 16:9], 59.94 fps, 59.94 tbr, 90k tbn, 119.88 tbc

    Stream #0:1[0x1100]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz,
5.1(side), fltp, 384 kb/s

    Stream #0:2[0x1200]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] /
0x0090), 1920x1080


And probe of filed generated via ffmpeg copy command:

ffprobe version N-64124-g84de3ed Copyright (c) 2007-2014 the FFmpeg
developers

  built on Jun 21 2014 17:13:02 with Apple LLVM version 5.1
(clang-503.0.40) (based on LLVM 3.4svn)

  configuration: --prefix=/Users/eugenegekhter/ffmpeg_build
--extra-cflags=-I/Users/eugenegekhter/ffmpeg_build/include
--extra-ldflags=-L/Users/eugenegekhter/ffmpeg_build/lib
--bindir=/Users/eugenegekhter/bin --extra-libs=-ldl --enable-gpl
--enable-libfdk-aac --enable-libx264 --enable-nonfree

  libavutil      52. 90.100 / 52. 90.100

  libavcodec     55. 68.100 / 55. 68.100

  libavformat    55. 44.100 / 55. 44.100

  libavdevice    55. 13.101 / 55. 13.101

  libavfilter     4.  9.100 /  4.  9.100

  libswscale      2.  6.100 /  2.  6.100

  libswresample   0. 19.100 /  0. 19.100

  libpostproc    52.  3.100 / 52.  3.100

Input #0, mpegts, from '/Users/eugenegekhter/Desktop/00013F.MTS':

  Duration: 00:02:40.19, start: 1.416678, bitrate: 26022 kb/s

  Program 1

    Metadata:

      service_name    : Service01

      service_provider: FFmpeg

    Stream #0:0[0x100]: Video: h264 (High) ([27][0][0][0] / 0x001B),
yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 59.94 fps, 59.94 tbr, 90k tbn,
119.88 tbc

    Stream #0:1[0x101]: Audio: ac3 ([129][0][0][0] / 0x0081), 48000 Hz,
5.1(side), fltp, 384 kb/s


If anybody has any input that would be greatly appreciated.


Thanks,



*Eugene Gekhter* / CEO

(847) 272-8207/ egekhter at pixcel.com
*Pixcel* Office: (800) 557-3508
3336 Commercial Ave. / Northbrook, IL 60062
http://www.pixcel.com