mov: error opening alias, while file exists

[Alex Zhukov]

​http://dl.dropbox.com/u/1109725/anonymous_theatrical_ref_1080p_2398_235.qt.gz
running ffmpeg -i on the file above wont find data file while the file actually exists and is readable

[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7f959303ea00] stream 0, error opening alias: path='/ds1_z800/444_EXTRA_1/{AD0E35C8-8D66-4DF5-8764-9E1F7FFE6CF6}/ds$theatrical_235@1920x1080c1 - 5522aac8#0000cmp.gen', dir='{AD0E35C8-8D66-4DF5-8764-9E1F7FFE6CF6}', filename='ds$theatrical_235@1920x1080c1 - 5522aac8#0000cmp.gen', volume='*', nlvl_from=-1, nlvl_to=-1

ls -la '/ds1_z800/444_EXTRA_1/{AD0E35C8-8D66-4DF5-8764-9E1F7FFE6CF6}/ds$theatrical_235@1920x1080c1 - 5522aac8#0000cmp.gen'

-rwxr-xr-x  2 tl_audio_node  staff  1551893467152 Dec 21 16:27 ds$theatrical_235@1920x1080c1 - 5522aac8#0000cmp.gen

tl-audio-node:~ tl_audio_node$ stat -x '/ds1_z800/444_EXTRA_1/{AD0E35C8-8D66-4DF5-8764-9E1F7FFE6CF6}/ds$theatrical_235@1920x1080c1 - 5522aac8#0000cmp.gen'
  File: "/ds1_z800/444_EXTRA_1/{AD0E35C8-8D66-4DF5-8764-9E1F7FFE6CF6}/ds$theatrical_235@1920x1080c1 - 5522aac8#0000cmp.gen"
  Size: 1551893467152  FileType: Regular File
  Mode: (0755/-rwxr-xr-x)         Uid: (  501/tl_audio_node)  Gid: (   20/   staff)
Device: 14,26   Inode: 50    Links: 2
Access: Mon Dec 12 18:53:20 2011
Modify: Wed Dec 21 16:27:32 2011
Change: Tue Jan  3 09:20:15 2012

[Carl Eugen Hoyos]

Please add command line (ffmpeg -i file) together with complete, uncut console output.

Does it work if the referenced files are not in an absolute, but a relative path?

[Alex Zhukov]

ffmpeg -i anonymous_theatrical_ref_1080p_2398_235.qt 
ffmpeg version N-36981-g9e53f62 Copyright (c) 2000-2012 the FFmpeg developers
  built on Jan 21 2012 09:24:49 with llvm_gcc 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.1.00)
  configuration: --enable-libopenjpeg
  libavutil      51. 34.101 / 51. 34.101
  libavcodec     53. 57.105 / 53. 57.105
  libavformat    53. 30.100 / 53. 30.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 59.101 /  2. 59.101
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  6.100 /  0.  6.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fe18983d800] stream 0, error opening alias: path='/ds1_z800/444_EXTRA_1/{AD0E35C8-8D66-4DF5-8764-9E1F7FFE6CF6}/ds$theatrical_235@1920x1080c1 - 5522aac8#0000cmp.gen', dir='{AD0E35C8-8D66-4DF5-8764-9E1F7FFE6CF6}', filename='ds$theatrical_235@1920x1080c1 - 5522aac8#0000cmp.gen', volume='*', nlvl_from=-1, nlvl_to=-1
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fe18983d800] stream 1, error opening alias: path='/ds1_z800/dS1_LOCALSTORAGE1/{AD0E35C8-8D66-4DF5-8764-9E1F7FFE6CF6}/audcachebbaa9a7b.wav', dir='{AD0E35C8-8D66-4DF5-8764-9E1F7FFE6CF6}', filename='audcachebbaa9a7b.wav', volume='*', nlvl_from=-1, nlvl_to=-1
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'anonymous_theatrical_ref_1080p_2398_235.qt':
  Metadata:
    major_brand     : qt  
    minor_version   : 537199360
    compatible_brands: qt  
    creation_time   : 2012-01-12 18:33:16
  Duration: 02:09:57.79, bitrate: 1 kb/s
    Stream #0:0(eng): Video: avrp (SUDS / 0x53445553), rgb48le, 1920x1080, 1590933 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 24k tbc
    Metadata:
      creation_time   : 2012-01-12 18:33:16
      handler_name    : ?Apple Alias Data Handler
    Stream #0:1(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, stereo, s32, 2304 kb/s
    Metadata:
      creation_time   : 2012-01-12 18:34:27
      handler_name    : ?Apple Alias Data Handler
At least one output file must be specified

[Carl Eugen Hoyos]

Does it work if the referenced files are not in an absolute, but a relative path?

[Alex Zhukov]

cd '/ds1_z800/444_EXTRA_1/{AD0E35C8-8D66-4DF5-8764-9E1F7FFE6CF6}/'
ffmpeg -i ~/ffmpeg/anonymous_theatrical_ref_1080p_2398_235.qt

same output
is this what you asked for?

[Carl Eugen Hoyos]

The reference in the file you posted does not point to a relative location like
"go/from/this/directory/to/the/next"
but an absolute one
"/it/starts/from/root"

The mov demuxer does not support absolute paths because the developers think that would be a possible security issue, but this could be circumvented with a command line switch.

But I wonder if it works with relative paths, perhaps you could also provide the referenced files, that would make testing easier.

[Alex Zhukov]

how can it be circumvented?
the following patch helped me

diff --git a/libavformat/mov.c b/libavformat/mov.c
index 3bb42fe..a58aa6f 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -1933,6 +1933,8 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
 static int mov_open_dref(AVIOContext **pb, const char *src, MOVDref *ref,
                          AVIOInterruptCB *int_cb)
 {
+    int i_know_what_i_am_doing_flag = 1; //TODO: get it from command-line or somewhere else
+    
     /* try relative path, we do not try the absolute because it can leak information about our
        system to an attacker */
     if (ref->nlvl_to > 0 && ref->nlvl_from > 0) {
@@ -1969,6 +1971,10 @@ static int mov_open_dref(AVIOContext **pb, const char *src, MOVDref *ref,
             if (!avio_open2(pb, filename, AVIO_FLAG_READ, int_cb, NULL))
                 return 0;
         }
+    } else if (i_know_what_i_am_doing_flag) {
+        //if user explicitly asks for absolute paths - try opening
+        if (!avio_open2(pb, ref->path, AVIO_FLAG_READ, int_cb, NULL))
+            return 0;
     }
 
     return AVERROR(ENOENT);

[Carl Eugen Hoyos]

Please test attached patch with ffmpeg -use_absolute_path 1 -i anonymous_theatrical_ref_1080p_2398_235.qt

[Alex Zhukov]

the patch works
thanks

[Carl Eugen Hoyos]

Should be fixed in current git head, thank you for testing!

[Matt]

Hi everyone,

I am new to ffmpeg and I recently ran into this same problem. Could some explain how to apply the patch? I am working on a windows static build here.

Thanks
Matt