[FFmpeg-devel] [PATCH v4 1/4] avformat/imf: Headers

[pal at sandflow.com]

From: Pierre-Anthony Lemieux <pal at palemieux.com>

Signed-off-by: Pierre-Anthony Lemieux <pal at palemieux.com>
---

Notes:
    The IMF demuxer accepts as input an IMF CPL. The assets referenced by the CPL can be
    contained in multiple deliveries, each defined by an ASSETMAP file:
    
    ffmpeg -assetmaps <path of ASSETMAP1>,<path of ASSETMAP>,... -i <path of CPL>
    
    If -assetmaps is not specified, FFMPEG looks for a file called ASSETMAP.xml in the same directory as the CPL.
    
    EXAMPLE:
        ffmpeg -i http://ffmpeg-imf-samples-public.s3-website-us-west-1.amazonaws.com/countdown/CPL_f5095caa-f204-4e1c-8a84-7af48c7ae16b.xml out.mp4
    
    The Interoperable Master Format (IMF) is a file-based media format for the
    delivery and storage of professional audio-visual masters.
    An IMF Composition consists of an XML playlist (the Composition Playlist)
    and a collection of MXF files (the Track Files). The Composition Playlist (CPL)
    assembles the Track Files onto a timeline, which consists of multiple tracks.
    The location of the Track Files referenced by the Composition Playlist is stored
    in one or more XML documents called Asset Maps. More details at https://www.imfug.com/explainer.
    The IMF standard was first introduced in 2013 and is managed by the SMPTE.
    
    Header and build files.
    
    CHANGE NOTES:
    
    - fixed patchwork warnings
    - updated patch notes
    - added LGPL license
    - removed imf_internal.h
    - Improve error handling, including removing exit()
    - Fix code style
    - Allow custom I/O for all files (following DASH and HLS template)
    - fix realloc memory leak

 libavformat/imf.h | 197 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 197 insertions(+)
 create mode 100644 libavformat/imf.h

diff --git a/libavformat/imf.h b/libavformat/imf.h
new file mode 100644
index 0000000000..59283a5d3a
--- /dev/null
+++ b/libavformat/imf.h
@@ -0,0 +1,197 @@
+/*
+ * Copyright (c) Sandflow Consulting LLC
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * Public header file for the processing of Interoperable Master Format (IMF) packages.
+ * 
+ * @author Pierre-Anthony Lemieux
+ * @author Valentin Noel
+ * @file
+ * @ingroup lavu_imf
+ */
+
+#ifndef AVFORMAT_IMF_H
+#define AVFORMAT_IMF_H
+
+#include "avformat.h"
+#include "libavformat/avio.h"
+#include "libavutil/rational.h"
+#include <libxml/tree.h>
+
+#define IMF_UUID_FORMAT "urn:uuid:%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
+
+/**
+ * UUID as defined in IETF RFC 422
+ */
+typedef uint8_t UUID[16];
+
+/**
+ * IMF Composition Playlist Base Resource
+ */
+typedef struct IMFBaseResource {
+    AVRational edit_rate; /**< BaseResourceType/EditRate */
+    unsigned long entry_point; /**< BaseResourceType/EntryPoint */
+    unsigned long duration; /**< BaseResourceType/Duration */
+    unsigned long repeat_count; /**< BaseResourceType/RepeatCount */
+} IMFBaseResource;
+
+/**
+ * IMF Composition Playlist Track File Resource
+ */
+typedef struct IMFTrackFileResource {
+    IMFBaseResource base;
+    UUID track_file_uuid; /**< TrackFileResourceType/TrackFileId */
+} IMFTrackFileResource;
+
+/**
+ * IMF Marker
+ */
+typedef struct IMFMarker {
+    xmlChar *label_utf8; /**< Marker/Label */
+    xmlChar *scope_utf8; /**< Marker/Label/\@scope */
+    unsigned long offset; /**< Marker/Offset */
+} IMFMarker;
+
+/**
+ * IMF Composition Playlist Marker Resource
+ */
+typedef struct IMFMarkerResource {
+    IMFBaseResource base;
+    unsigned long marker_count; /**< Number of Marker elements */
+    IMFMarker *markers; /**< Marker elements */
+} IMFMarkerResource;
+
+/**
+ * IMF Composition Playlist Virtual Track
+ */
+typedef struct IMFBaseVirtualTrack {
+    UUID id_uuid; /**< TrackId associated with the Virtual Track */
+} IMFBaseVirtualTrack;
+
+/**
+ * IMF Composition Playlist Virtual Track that consists of Track File Resources
+ */
+typedef struct IMFTrackFileVirtualTrack {
+    IMFBaseVirtualTrack base;
+    unsigned long resource_count; /**< Number of Resource elements present in the Virtual Track */
+    IMFTrackFileResource *resources; /**< Resource elements of the Virtual Track */
+} IMFTrackFileVirtualTrack;
+
+/**
+ * IMF Composition Playlist Virtual Track that consists of Marker Resources
+ */
+typedef struct IMFMarkerVirtualTrack {
+    IMFBaseVirtualTrack base;
+    unsigned long resource_count; /**< Number of Resource elements present in the Virtual Track */
+    IMFMarkerResource *resources; /**< Resource elements of the Virtual Track */
+} IMFMarkerVirtualTrack;
+
+/**
+ * IMF Composition Playlist
+ */
+typedef struct IMFCPL {
+    UUID id_uuid; /**< CompositionPlaylist/Id element */
+    xmlChar *content_title_utf8; /**< CompositionPlaylist/ContentTitle element */
+    AVRational edit_rate; /**< CompositionPlaylist/EditRate element */
+    IMFMarkerVirtualTrack *main_markers_track; /**< Main Marker Virtual Track */
+    IMFTrackFileVirtualTrack *main_image_2d_track; /**< Main Image Virtual Track */
+    unsigned long main_audio_track_count; /**< Number of Main Audio Virtual Tracks */
+    IMFTrackFileVirtualTrack *main_audio_tracks; /**< Main Audio Virtual Tracks */
+} IMFCPL;
+
+/**
+ * Parse an IMF CompositionPlaylist element into the IMFCPL data structure.
+ * @param[in] doc An XML document from which the CPL is read.
+ * @param[out] cpl Pointer to a memory area (allocated by the client), where the function writes a pointer to the newly constructed
+ * IMFCPL structure (or NULL if the CPL could not be parsed). The client is responsible for freeing the IMFCPL structure using
+ * imf_cpl_free().
+ * @return A non-zero value in case of an error.
+ */
+int parse_imf_cpl_from_xml_dom(xmlDocPtr doc, IMFCPL **cpl);
+
+/**
+ * Parse an IMF Composition Playlist document into the IMFCPL data structure.
+ * @param[in] in The context from which the CPL is read.
+ * @param[out] cpl Pointer to a memory area (allocated by the client), where the function writes a pointer to the newly constructed
+ * IMFCPL structure (or NULL if the CPL could not be parsed). The client is responsible for freeing the IMFCPL structure using
+ * imf_cpl_free().
+ * @return A non-zero value in case of an error.
+ */
+int parse_imf_cpl(AVIOContext *in, IMFCPL **cpl);
+
+/**
+ * Allocates and initializes an IMFCPL data structure.
+ * @return A pointer to the newly constructed IMFCPL structure (or NULL if the structure could not be constructed). The client is
+ * responsible for freeing the IMFCPL structure using imf_cpl_free().
+ */
+IMFCPL *imf_cpl_alloc(void);
+
+/**
+ * Deletes an IMFCPL data structure previously instantiated with imf_cpl_alloc().
+ * @param[in] cpl The IMFCPL structure to delete.
+ */
+void imf_cpl_free(IMFCPL *cpl);
+
+/**
+ * Reads an unsigned long from an XML element
+ * @return 0 on success, < 0 AVERROR code on error.
+ */
+int imf_xml_read_ulong(xmlNodePtr element, unsigned long *number);
+
+/**
+ * Reads an AVRational from an XML element
+ * @return 0 on success, < 0 AVERROR code on error.
+ */
+int imf_xml_read_rational(xmlNodePtr element, AVRational *rational);
+
+/**
+ * Reads a UUID from an XML element
+ * @return 0 on success, < 0 AVERROR code on error.
+ */
+int imf_xml_read_UUID(xmlNodePtr element, uint8_t uuid[16]);
+
+/**
+ * Returns the first child element with the specified local name
+ * @return A pointer to the child element, or NULL if no such child element exists.
+ */
+xmlNodePtr imf_xml_get_child_element_by_name(xmlNodePtr parent, const char *name_utf8);
+
+#endif
-- 
2.17.1