lavf: add libxml2-based ASX playlist demuxer.

4 files changed, 188 insertions, 0 deletions

diff --git a/configure b/configure
index f5a285e6d1..d9fc8e2645 100755
--- a/configure
+++ b/configure
@@ -187,6 +187,7 @@ External library support:
   --enable-libvpx          enable VP8 support via libvpx [no]
   --enable-libx264         enable H.264 encoding via x264 [no]
   --enable-libxavs         enable AVS encoding via xavs [no]
+  --enable-libxml2         enable libxml2 (needed for asx demuxing) [no]
   --enable-libxvid         enable Xvid encoding via xvidcore,
                            native MPEG-4/Xvid encoder exists [no]
   --enable-mlib            enable Sun medialib [no]
@@ -950,6 +951,7 @@ CONFIG_LIST="
     libvpx
     libx264
     libxavs
+    libxml2
     libxvid
     lpc
     lsp
@@ -1419,6 +1421,7 @@ libxvid_encoder_deps="libxvid"
 # demuxers / muxers
 ac3_demuxer_select="ac3_parser"
 asf_stream_muxer_select="asf_muxer"
+asx_demuxer_deps="libxml2"
 avisynth_demuxer_deps="avisynth"
 dirac_demuxer_select="dirac_parser"
 eac3_demuxer_select="ac3_parser"
@@ -2908,6 +2911,7 @@ enabled libx264    && require  libx264 x264.h x264_encoder_encode -lx264 &&
                       { check_cpp_condition x264.h "X264_BUILD >= 115" ||
                         die "ERROR: libx264 version must be >= 0.115."; }
 enabled libxavs    && require  libxavs xavs.h xavs_encoder_encode -lxavs
+enabled libxml2    && require_pkg_config libxml-2.0 libxml/xmlreader.h xmlReaderForIO
 enabled libxvid    && require  libxvid xvid.h xvid_global -lxvidcore
 enabled mlib       && require  mediaLib mlib_types.h mlib_VectorSub_S16_U8_Mod -lmlib
 
@@ -3187,6 +3191,7 @@ echo "libvorbis enabled         ${libvorbis-no}"
 echo "libvpx enabled            ${libvpx-no}"
 echo "libx264 enabled           ${libx264-no}"
 echo "libxavs enabled           ${libxavs-no}"
+echo "libxml2 enabled           ${libxml2-no}"
 echo "libxvid enabled           ${libxvid-no}"
 echo "zlib enabled              ${zlib-no}"
 echo "bzlib enabled             ${bzlib-no}"
diff --git a/libavformat/Makefile b/libavformat/Makefile
index b1e8ed18d0..9253d13c7a 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -35,6 +35,7 @@ OBJS-$(CONFIG_ASF_DEMUXER)               += asfdec.o asf.o asfcrypt.o \
 OBJS-$(CONFIG_ASF_MUXER)                 += asfenc.o asf.o riff.o
 OBJS-$(CONFIG_ASS_DEMUXER)               += assdec.o
 OBJS-$(CONFIG_ASS_MUXER)                 += assenc.o
+OBJS-$(CONFIG_ASX_DEMUXER)               += asxdec.o
 OBJS-$(CONFIG_AU_DEMUXER)                += au.o pcm.o
 OBJS-$(CONFIG_AU_MUXER)                  += au.o
 OBJS-$(CONFIG_AVI_DEMUXER)               += avidec.o riff.o avi.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 5bfd840f3f..bbea23ecfc 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -62,6 +62,7 @@ void av_register_all(void)
     REGISTER_MUXDEMUX (ASF, asf);
     REGISTER_MUXDEMUX (ASS, ass);
     REGISTER_MUXER    (ASF_STREAM, asf_stream);
+    REGISTER_DEMUXER  (ASX, asx);
     REGISTER_MUXDEMUX (AU, au);
     REGISTER_MUXDEMUX (AVI, avi);
     REGISTER_DEMUXER  (AVISYNTH, avisynth);
diff --git a/libavformat/asxdec.c b/libavformat/asxdec.c
new file mode 100644
index 0000000000..a6218697be
--- /dev/null
+++ b/libavformat/asxdec.c
@@ -0,0 +1,181 @@
+/*
+ * ASX playlist demuxer.
+ * Copyright (c) 2011 Anton Khirnov
+ *
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "avformat.h"
+#include "internal.h"
+#include "playlist.h"
+
+#include "libavutil/avstring.h"
+#include "libavutil/dict.h"
+#include "libavutil/log.h"
+#include "libavutil/mem.h"
+
+#include <strings.h>
+
+#include <libxml/xmlreader.h>
+
+/**
+ * Find an attribute using case-insensitive matching.
+ */
+static int asx_find_attribute(xmlTextReader *reader, const uint8_t *name)
+{
+    while (xmlTextReaderMoveToNextAttribute(reader) == 1)
+        if (!strcasecmp(xmlTextReaderConstName(reader), name))
+            return 1;
+    return 0;
+}
+
+static int asx_read_metadata(xmlTextReader *reader, AVDictionary **metadata)
+{
+    const uint8_t *key = xmlTextReaderConstName(reader);
+
+    if (xmlTextReaderRead(reader) != 1 ||
+        xmlTextReaderNodeType(reader) != XML_READER_TYPE_TEXT)
+        return 0;
+    return av_dict_set(metadata, key, xmlTextReaderConstValue(reader), 0);
+}
+
+static int asx_read_ref(AVFormatContext *s, xmlTextReader *reader, AVPlaylistElement **elem)
+{
+    if (!asx_find_attribute(reader, "HREF")) {
+        av_log(s, AV_LOG_WARNING, "No URL in a REF element, skipping.\n");
+        return 0;
+    }
+
+    if (*elem) {
+        AVPlaylistElement *e = *elem;
+        uint8_t *filename = av_strdup(xmlTextReaderConstValue(reader));
+        dynarray_add(&e->filenames, &e->nb_filenames, filename);
+    } else
+        *elem = ff_playlist_add_entry(s, xmlTextReaderConstValue(reader));
+
+    if (!*elem)
+        return AVERROR(ENOMEM);
+
+    // TODO: parse children
+    return 0;
+}
+
+static int asx_read_entry(AVFormatContext *s, xmlTextReader *reader)
+{
+    int ret;
+
+    if (xmlTextReaderIsEmptyElement(reader)) {
+        // there's an undocumented example in the specs using this syntax
+        if (asx_find_attribute(reader, "HREF"))
+            ff_playlist_add_entry(s, xmlTextReaderConstValue(reader));
+        else
+            av_log(s, AV_LOG_WARNING, "Empty ENTRY element.\n");
+    } else {
+        int cur_depth = xmlTextReaderDepth(reader);
+        AVDictionary  *metadata = NULL;
+        AVPlaylistElement *elem = NULL;
+
+        while (xmlTextReaderRead(reader) == 1 &&
+               !(xmlTextReaderNodeType(reader) == XML_READER_TYPE_END_ELEMENT &&
+                 xmlTextReaderDepth(reader)    == cur_depth)) {
+            if (xmlTextReaderNodeType(reader) != XML_READER_TYPE_ELEMENT ||
+                xmlTextReaderDepth(reader)    != cur_depth + 1)
+                continue;
+
+            if (!strcasecmp(xmlTextReaderConstName(reader), "ref"))
+                ret = asx_read_ref(s, reader, &elem);
+            else
+                ret = asx_read_metadata(reader, &metadata);
+
+            if (ret < 0)
+                return ret;
+        }
+        if (elem)
+            elem->metadata = metadata;
+        else
+            av_log(s, AV_LOG_WARNING, "No REF element in an entry, skipping.\n");
+    }
+
+    return 0;
+}
+
+/**
+ * avio_read() wrapper, translates avio errors into libxml2 errors
+ */
+static int asx_read_callback(AVIOContext *s, char *buf, int len)
+{
+    int ret = avio_read(s, buf, len);
+
+    if (ret >= 0)
+        return ret;
+    else if (ret == AVERROR_EOF)
+        return 0;
+    else
+        return -1;
+}
+
+static int asx_read_header(AVFormatContext *s, AVFormatParameters *ap)
+{
+    int ret = 0;
+    xmlTextReader *reader;
+
+    if (!(reader = xmlReaderForIO((xmlInputReadCallback)asx_read_callback, NULL, s->pb, s->filename, NULL, 0))) {
+        av_log(s, AV_LOG_ERROR, "Could not create XML reader.\n");
+        return AVERROR(EIO);
+    }
+
+    if (xmlTextReaderRead(reader) != 1 || strcasecmp(xmlTextReaderConstName(reader), "ASX")) {
+        av_log(s, AV_LOG_ERROR, "File does not start with an ASX element.\n");
+        ret = AVERROR_INVALIDDATA;
+        goto finish;
+    }
+
+    while (xmlTextReaderRead(reader) == 1 &&
+           !(xmlTextReaderNodeType(reader) == XML_READER_TYPE_END_ELEMENT &&
+             xmlTextReaderDepth(reader)    == 0)) {
+        const uint8_t *name;
+
+        // find next top-level element
+        if (xmlTextReaderNodeType(reader) != XML_READER_TYPE_ELEMENT ||
+            xmlTextReaderDepth(reader) != 1)
+            continue;
+
+        name = xmlTextReaderConstName(reader);
+        if      (!strcasecmp(name, "entry")) ret = asx_read_entry(s, reader);
+        else                                 ret = asx_read_metadata(reader, &s->metadata);
+
+        if (ret < 0)
+            goto finish;
+    }
+
+finish:
+    xmlFreeTextReader(reader);
+    return ret;
+}
+
+static int asx_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    return AVERROR_EOF;
+}
+
+AVInputFormat ff_asx_demuxer = {
+    .name        = "ASX",
+    .long_name   = "Advanced Stream Redirector",
+    .read_header = asx_read_header,
+    .read_packet = asx_read_packet,
+    .extensions  = "asx,wvx,wax",
+};