[vlc-commits] discard image and mjpeg demuxers in case of mxpeg

[Sébastien Escudier]

vlc | branch: master | Sébastien Escudier <sebastien-devel at celeos.eu> | Fri Feb 10 15:14:43 2012 +0100| [2985b7fe1755b8bc3b3e7c01cb1bc4f92b770791] | committer: Sébastien Escudier

discard image and mjpeg demuxers in case of mxpeg

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=2985b7fe1755b8bc3b3e7c01cb1bc4f92b770791
---

 modules/demux/Modules.am     |    4 +-
 modules/demux/image.c        |    9 ++++
 modules/demux/mjpeg.c        |    7 +++
 modules/demux/mxpeg_helper.h |   89 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 107 insertions(+), 2 deletions(-)

diff --git a/modules/demux/Modules.am b/modules/demux/Modules.am
index 503facc..6926361 100644
--- a/modules/demux/Modules.am
+++ b/modules/demux/Modules.am
@@ -15,7 +15,7 @@ SOURCES_ps = ps.c ps.h
 SOURCES_mod = mod.c dummy.cpp
 SOURCES_pva = pva.c
 SOURCES_aiff = aiff.c
-SOURCES_mjpeg = mjpeg.c
+SOURCES_mjpeg = mjpeg.c mxpeg_helper.h
 SOURCES_subtitle = subtitle.c
 SOURCES_ty = ty.c ../codec/cc.h
 SOURCES_vobsub = vobsub.c vobsub.h
@@ -31,7 +31,7 @@ SOURCES_smf = smf.c
 SOURCES_gme = gme.c dummy.cpp
 SOURCES_sid = sid.cpp
 SOURCES_dirac = dirac.c
-SOURCES_image = image.c
+SOURCES_image = image.c mxpeg_helper.h
 SOURCES_demux_stl = stl.c
 
 libvlc_LTLIBRARIES += \
diff --git a/modules/demux/image.c b/modules/demux/image.c
index f2fb8ac..021f122 100644
--- a/modules/demux/image.c
+++ b/modules/demux/image.c
@@ -33,6 +33,7 @@
 #include <vlc_plugin.h>
 #include <vlc_demux.h>
 #include <vlc_image.h>
+#include "mxpeg_helper.h"
 
 /*****************************************************************************
  * Module descriptor
@@ -525,6 +526,9 @@ static const image_format_t formats[] = {
     { .codec = VLC_CODEC_PNM,
       .detect = IsPnm,
     },
+    { .codec = VLC_CODEC_MXPEG,
+      .detect = IsMxpeg,
+    },
     { .codec = VLC_CODEC_JPEG,
       .detect = IsJfif,
     },
@@ -568,6 +572,11 @@ static int Open(vlc_object_t *object)
     msg_Dbg(demux, "Detected image: %s",
             vlc_fourcc_GetDescription(VIDEO_ES, img->codec));
 
+    if( img->codec == VLC_CODEC_MXPEG )
+    {
+        return VLC_EGENERIC; //let avformat demux this file
+    }
+
     /* Load and if selected decode */
     es_format_t fmt;
     es_format_Init(&fmt, VIDEO_ES, img->codec);
diff --git a/modules/demux/mjpeg.c b/modules/demux/mjpeg.c
index afdc484..07d9e1b 100644
--- a/modules/demux/mjpeg.c
+++ b/modules/demux/mjpeg.c
@@ -35,6 +35,7 @@
 #include <vlc_common.h>
 #include <vlc_plugin.h>
 #include <vlc_demux.h>
+#include "mxpeg_helper.h"
 
 /*****************************************************************************
  * Module descriptor
@@ -316,6 +317,12 @@ static int Open( vlc_object_t * p_this )
     p_sys->psz_separator = NULL;
     p_sys->i_frame_size_estimate = 15 * 1024;
 
+    if( IsMxpeg( p_demux->s ) && !p_demux->b_force )
+    {
+        // let avformat handle this case
+        goto error;
+    }
+
     b_matched = CheckMimeHeader( p_demux, &i_size);
     if( b_matched )
     {
diff --git a/modules/demux/mxpeg_helper.h b/modules/demux/mxpeg_helper.h
new file mode 100644
index 0000000..76305c6
--- /dev/null
+++ b/modules/demux/mxpeg_helper.h
@@ -0,0 +1,89 @@
+/*****************************************************************************
+ * mxpeg_helper.h: MXPEG helper functions
+ *****************************************************************************
+ * Copyright (C) 2012 the VideoLAN team
+ * $Id$
+ *
+ * Authors: Sébastien Escudier
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+/**
+ * Finds FF XX in the first size byte of data
+ */
+static uint8_t find_jpeg_marker(int *position, const uint8_t *data, int size)
+{
+    for (int i = *position; i + 1 < size; i++) {
+        if (data[i] != 0xff)
+            continue;
+        if (data[i + 1] != 0xff) {
+            *position = i + 2;
+            return data[i + 1];
+        }
+    }
+    return 0xff;
+}
+
+/*
+ * Mxpeg frame format : http://developer.mobotix.com/docs/mxpeg_frame.html
+ * */
+static bool IsMxpeg(stream_t *s)
+{
+    const uint8_t *header;
+    int size = stream_Peek(s, &header, 256);
+    int position = 0;
+
+    if (find_jpeg_marker(&position, header, size) != 0xd8)
+        return false;
+    if (find_jpeg_marker(&position, header, position + 2) != 0xe0)
+        return false;
+
+    if (position + 2 > size)
+        return false;
+
+    /* Skip this jpeg header */
+    uint32_t header_size = GetWBE(&header[position]);
+    position += header_size;
+    if (position + 4 > size)
+    {
+        size = position + 4;
+        if( stream_Peek (s, &header, size) < size )
+            return false;
+    }
+
+    /* Skip the comment header */
+    if ( !(header[position] == 0xFF && header[position+1] == 0xFE) )
+        return false;
+
+    position += 2;
+    header_size = GetWBE (&header[position]);
+
+    /* Find the MXF header */
+    size = position + header_size + 8; //8 = FF FE 00 00 M X F 00
+    if (stream_Peek(s, &header, position + header_size + 8 ) < size)
+        return false;
+
+    position += header_size;
+    if ( !(header[position] == 0xFF && header[position+1] == 0xFE) )
+        return false;
+
+    position += 4;
+
+    if (memcmp (&header[position], "MXF\0", 4) )
+        return false;
+
+    return true;
+}