Metadata

Motivation

All the Xiph.org codecs have some internal mechanism for including metadata about the current stream. Generally, this is one of the codec headers, and in the words of the vorbis spec, "It is meant for short, text comments...much like someone jotting a quick note on the bottom of a CDR."

This works well enough for most things, and can be overloaded/abused (depending on your point of view) for most other things. But there are three major requirements that point to the design of an external metadata format; one that can be interleaved with the other streams in a container.

• Machinability There are a number of items of metadata that a player will want to parse and take action on. While there are usually 'convention' schemes for doing this with the embedded comment headers, this is much easier if there is a separate metadata stream designed for such use, instead of having to do best-effort parsing of natural language comments. For example, a video file with multiple audio tracks can specify the language of each one; a player than can parse these reliably can match them against a language preference list configured by the user to automatically select and begin playback of the best option.

• Kitchen Sink There are a minority of people who care passionately about having every detail about a track available. In the sense of conserving such information, and providing an equivalent to liner notes for online distribution, this is a goal worth supporting. However, the simple unstructured key-value pairs offered by the inline metadata are unwieldy for this level of detail. How do you tell the 2nd unit Assistant Director from the USA unit Assistant Director? How do you indicate which artist played tenor sax in the solo?

• Addressability The internal comment metadata headers are by necessity attached to a single content stream. This is useful for some appication, but a limitation in others. In a multiplexed stream, which set of comments refers to the collection as a whole? (By convention, in Ogg, it's the first logical bitstream occuring, but we can do better.) A separate metadata stream type must address this issue of collective metadata while still allowing description of individual streams. It should also allow temporal addressability, so that changes can be described. Because the in-stream comment metadata are part of the codec headers, it cannot change over the course of the stream, and allowing additional comment packets elsewhere in the stream presents seeking challenges. In the Ogg container this can be resolved by inserting a chain boundary, but this is a poor option for very-low-bitrate streams and unreliable transports such as RTP.

Proposed Solutions

RDF + dublin core

XML-encoding (generic rdf or CMML?) binary encoding (three-component length-encoded binary vectors) 107粘合剂 内墙涂料 内外浸塑防腐管道 内外墙涂料 内外墙专用腻子粉 纳米丙稀酸外墙乳胶漆 纳米材料 纳米改性氟碳涂料 纳米涂料 纳米余辉自发光涂料 耐腐蚀树脂 耐高温特种涂料 耐磨地坪骨料 耐磨地坪漆 偶联剂 哌啶系列衍生物 膨胀型过氯乙烯 皮带运输机自动纠偏装置 皮具边油 偏苯三酸酐 企口漆 汽车门窗密封条植绒胶粘剂 汽车密封胶 汽车漆 汽车涂料 汽车修补漆 汽油辛烷 强膜防水漆 羟基硅油 羟基乙腈 清漆 全丙高弹性外墙乳胶漆 全天候硅丙外墙漆 全息铝箔 全息烟膜 热固化阻焊油墨 热固性半光无光型粉末 热固性粉末 热固性粉末涂料 热固性环氧 热固性环氧聚酯粉末涂料 热固性环氧型粉末涂料 重防腐油漆 助流剂 转炉喷补料 转移膜 装饰美术纹理型粉末涂料 装饰纸色浆 装修漆 紫外固化 紫外光固化 紫外光固化产品 紫外光固化涂料 紫外光硬化阻焊油墨 自动涂装生产 自乳化丙烯酸环氧树脂 阻聚剂 阻燃剂 阻燃两用装修漆 阻燃吸音装饰板 钻井泥浆助剂 醋酸丁酯和乙酯 醋酸乙烯无光乳胶漆 大孔螯合型离子交换树脂 单力建筑胶 弹性凹凸漆 弹性建筑密封胶 弹性胶浆 弹性涂料 弹性质感涂料 导电漆 导静电地坪涂料 道路沥青 灯用卤磷酸钙荧光粉 低温固化粉末型 底色漆 地板漆 地坪涂料 电线瓷瓶 饺子模 结构胶 界面剂 金刚石磨轮 金属防腐蚀专用涂料 金属漆 金属闪光漆 金属外壳涂装 金属装饰漆 浸渍料 静电喷涂 静电涂装成套设备 静电植绒胶 聚氨脂灌封料 聚氨酯 聚氨酯单组份防腐漆 聚氨酯粉末涂料 聚氨酯互穿网络防腐涂料 硬胶漆 硬脂酸 硬脂酸锌 硬质UV哑光涂料 硬质UV罩光涂 硬质UV罩光涂料 硬质聚氨酯泡沫 钢结构防火涂料 钢结构隔热 钢性抗渗腻子 高档环保水性建筑涂料 高档聚酯漆 高分子助剂 高光外墙专用乳液 高级彩色瓦面漆 高级彩色屋面防水涂料 高级防火涂料 高级聚氨酯漆 高级闪光雨线 高级丝光乳胶漆 蓝色粉末材料 镭射烟用衬纸 冷库硬质聚氨酯泡沫 冷施工橡塑防水防腐涂料 连铸保护渣 亮光耐酒精硬胶油墨 邻苯二甲酸二丁酯 磷化液 流平剂 流态化石灰粉 热固性聚酯型粉末涂料 热固性美术纹理型粉末涂料 热喷涂锌 热熔反光标线涂料 热熔性树脂 热塑涂料 人造大理石 溶剂型工业涂料 溶剂型聚酰 溶剂型聚酰胺 有机硅改性丙烯酸外墙涂料 鞣剂 乳胶漆 乳液 锐钛型钛白粉 三聚氯氰 三片金属罐外涂料 三羟甲基丙烷三丙烯酸酯 三嗪类除草剂 三烷基 三元乙丙橡胶 色标卡 深酞兰氨基面漆 石材防护剂 石头漆 食品级氟涂料 室内乳胶漆 室温固化31570X 兽用抗生素原料药 叔丙乳液 叔醋乳液 树脂 树脂胶版油墨 树脂类地坪 双组份烤漆 水不漏 水处理产品 水墨 水性氟碳漆 水性工业涂料 水性光油 水性环保型功能性涂料 水性涂料 水性助剂 水性自乳化双酚A环氧树脂 丝光乳胶漆 丝面漆专用乳液 丝网油墨 塑胶UV上光油 塑料薄膜油墨 塑料助剂 碳钢食品容器内壁防腐涂料 陶瓷粉 特富龙涂料 特种工业涂料 特种油墨 天然真石漆 填眼灰 铁沟捣打料 涂料色浆 涂料用丙烯酸树脂 涂料用树脂 脱塑剂 外墙平涂类 外墙普通面涂料 外墙涂料 外墙有色底涂料 万能胶 网版印刷油墨 微型球铝粉 无苯稀释剂 无毒固化剂 无毒玩具漆 无毒无溶剂涂料 五氧化二钒 吸附树脂 象牙白氨基面漆 橡胶金属热硫化胶粘剂 橡胶漆 消泡剂 硝基类系列涂料 硝基漆 鞋材油漆 仿瓷涂料 水性防瓷釉涂料 压裂弹 压敏陶瓷 哑光厚质高弹弹性乳胶漆 亚光内墙乳胶 亚光内墙乳胶漆 岩棉制品 颜料糊 氧化络绿 液体氰化钠 乙烯基异丁基醚 乙烯基酯 乙氧基化 异氰酸酯 印花色浆 印花粘合剂 印刷包装胶粘剂 油封 油漆催干剂 油漆专用稀释剂 油田污水处理系列药剂 油性丙烯酸树脂 油性高抗碱底漆 有机膨润土 有机锡 玉石钢化涂料 原子灰 增稠剂 增密双层胶辊 粘合粘合剂 珍珠白氨基面漆 振利保温材料 振利涂料 整体耐磨防腐地面涂料 纸品UV涂料 制革助剂 中间包喷涂料 中密度纤维板 中涂漆 种子包衣剂 本色漆 http://www.shop263.com/i-45/1.htm http://www.shop263.com/i-45/2.htm http://www.shop263.com/i-45/3.htm http://www.shop263.com/i-45/4.htm http://www.shop263.com/i-45/5.htm http://www.shop263.com/i-45/6.htm http://www.shop263.com/i-45/7.htm http://www.shop263.com/i-45/8.htm http://www.shop263.com/i-45/9.htm http://www.shop263.com/i-45/10.htm http://www.shop263.com/i-45/11.htm http://www.shop263.com/i-45/12.htm http://www.shop263.com/i-45/13.htm http://www.shop263.com/i-45/14.htm http://www.shop263.com/i-45/15.htm http://www.shop263.com/i-45/16.htm http://www.shop263.com/i-45/17.htm http://www.shop263.com/i-45/18.htm http://www.shop263.com/i-45/19.htm http://www.shop263.com/i-45/20.htm http://www.shop263.com/i-45/21.htm http://www.shop263.com/i-45/22.htm http://www.shop263.com/i-45/23.htm http://www.shop263.com/i-45/24.htm http://www.shop263.com/i-45/25.htm http://www.shop263.com/i-45/26.htm http://www.shop263.com/i-45/27.htm http://www.shop263.com/i-45/28.htm http://www.shop263.com/i-45/29.htm http://www.shop263.com/i-45/30.htm http://www.shop263.com/i-45/31.htm http://www.shop263.com/i-45/32.htm http://www.shop263.com/i-45/33.htm http://www.shop263.com/i-45/34.htm http://www.shop263.com/i-45/35.htm http://www.shop263.com/i-45/36.htm http://www.shop263.com/i-45/37.htm http://www.shop263.com/i-45/38.htm http://www.shop263.com/i-45/39.htm http://www.shop263.com/i-45/40.htm http://www.shop263.com/i-45/41.htm http://www.shop263.com/i-45/42.htm http://www.shop263.com/i-45/43.htm http://www.shop263.com/i-45/44.htm http://www.shop263.com/i-45/45.htm http://www.shop263.com/i-45/46.htm http://www.shop263.com/i-45/47.htm http://www.shop263.com/i-45/48.htm http://www.shop263.com/i-45/49.htm http://www.shop263.com/i-45/50.htm http://www.shop263.com/i-45/51.htm http://www.shop263.com/i-45/52.htm http://www.shop263.com/i-45/53.htm http://www.shop263.com/i-45/54.htm http://www.shop263.com/i-45/55.htm http://www.shop263.com/i-45/56.htm http://www.shop263.com/i-45/57.htm http://www.shop263.com/i-45/58.htm http://www.shop263.com/i-45/59.htm http://www.shop263.com/i-45/60.htm http://www.shop263.com/i-45/61.htm http://www.shop263.com/i-45/62.htm http://www.shop263.com/i-45/63.htm http://www.shop263.com/i-45/64.htm http://www.shop263.com/i-45/65.htm http://www.shop263.com/i-45/66.htm http://www.shop263.com/i-45/67.htm http://www.shop263.com/i-45/68.htm http://www.shop263.com/i-45/69.htm http://www.shop263.com/i-45/70.htm http://www.shop263.com/i-45/71.htm http://www.shop263.com/i-45/72.htm http://www.shop263.com/i-45/73.htm http://www.shop263.com/i-45/74.htm http://www.shop263.com/i-45/75.htm http://www.shop263.com/i-45/76.htm http://www.shop263.com/i-45/77.htm http://www.shop263.com/i-45/78.htm http://www.shop263.com/i-45/79.htm http://www.shop263.com/i-45/80.htm http://www.shop263.com/i-45/81.htm http://www.shop263.com/i-45/82.htm http://www.shop263.com/i-45/83.htm http://www.shop263.com/i-45/84.htm http://www.shop263.com/i-45/85.htm http://www.shop263.com/i-45/86.htm http://www.shop263.com/i-45/87.htm http://www.shop263.com/i-45/88.htm http://www.shop263.com/i-45/89.htm http://www.shop263.com/i-45/90.htm http://www.shop263.com/i-45/91.htm http://www.shop263.com/i-45/92.htm http://www.shop263.com/i-45/93.htm http://www.shop263.com/i-45/94.htm http://www.shop263.com/i-45/95.htm http://www.shop263.com/i-45/96.htm http://www.shop263.com/i-45/97.htm http://www.shop263.com/i-45/98.htm http://www.shop263.com/i-45/99.htm http://www.shop263.com/i-45/100.htm http://www.shop263.com/i-45/101.htm http://www.shop263.com/i-45/102.htm http://www.shop263.com/i-45/103.htm http://www.shop263.com/i-45/104.htm http://www.shop263.com/i-45/105.htm http://www.shop263.com/i-45/106.htm http://www.shop263.com/i-45/107.htm http://www.shop263.com/i-45/108.htm http://www.shop263.com/i-45/109.htm http://www.shop263.com/i-45/110.htm http://www.shop263.com/i-45/111.htm http://www.shop263.com/i-45/112.htm http://www.shop263.com/i-45/113.htm http://www.shop263.com/i-45/114.htm http://www.shop263.com/i-45/115.htm http://www.shop263.com/i-45/116.htm http://www.shop263.com/i-45/117.htm http://www.shop263.com/i-45/118.htm http://www.shop263.com/i-45/119.htm http://www.shop263.com/i-45/120.htm http://www.shop263.com/i-45/121.htm http://www.shop263.com/i-45/122.htm http://www.shop263.com/i-45/123.htm http://www.shop263.com/i-45/124.htm http://www.shop263.com/i-45/125.htm http://www.shop263.com/i-45/126.htm http://www.shop263.com/i-45/127.htm http://www.shop263.com/i-45/128.htm http://www.shop263.com/i-45/129.htm http://www.shop263.com/i-45/130.htm http://www.shop263.com/i-45/131.htm http://www.shop263.com/i-45/132.htm http://www.shop263.com/i-45/133.htm http://www.shop263.com/i-45/134.htm http://www.shop263.com/i-45/135.htm http://www.shop263.com/i-45/136.htm http://www.shop263.com/i-45/137.htm http://www.shop263.com/i-45/138.htm http://www.shop263.com/i-45/139.htm http://www.shop263.com/i-45/140.htm http://www.shop263.com/i-45/141.htm http://www.shop263.com/i-45/142.htm http://www.shop263.com/i-45/143.htm http://www.shop263.com/i-45/144.htm http://www.shop263.com/i-45/145.htm http://www.shop263.com/i-45/146.htm http://www.shop263.com/i-45/147.htm http://www.shop263.com/i-45/148.htm http://www.shop263.com/i-45/149.htm http://www.shop263.com/i-45/150.htm http://www.shop263.com/i-45/151.htm http://www.shop263.com/i-45/152.htm http://www.shop263.com/i-45/153.htm http://www.shop263.com/i-45/154.htm http://www.shop263.com/i-45/155.htm http://www.shop263.com/i-45/156.htm http://www.shop263.com/i-45/157.htm http://www.shop263.com/i-45/158.htm http://www.shop263.com/i-45/159.htm http://www.shop263.com/i-45/160.htm http://www.shop263.com/i-45/161.htm http://www.shop263.com/i-45/162.htm http://www.shop263.com/i-45/163.htm http://www.shop263.com/i-45/164.htm http://www.shop263.com/i-45/165.htm http://www.shop263.com/i-45/166.htm http://www.shop263.com/i-45/167.htm http://www.shop263.com/i-45/168.htm http://www.shop263.com/i-45/169.htm http://www.shop263.com/i-45/170.htm http://www.shop263.com/i-45/171.htm http://www.shop263.com/i-45/172.htm http://www.shop263.com/i-45/173.htm http://www.shop263.com/i-45/174.htm http://www.shop263.com/i-45/175.htm http://www.shop263.com/i-45/176.htm http://www.shop263.com/i-45/177.htm http://www.shop263.com/i-45/178.htm http://www.shop263.com/i-45/179.htm http://www.shop263.com/i-45/180.htm http://www.shop263.com/i-45/181.htm http://www.shop263.com/i-45/182.htm http://www.shop263.com/i-45/183.htm http://www.shop263.com/i-45/184.htm http://www.shop263.com/i-45/185.htm http://www.shop263.com/i-45/186.htm http://www.shop263.com/i-45/187.htm http://www.shop263.com/i-45/188.htm http://www.shop263.com/i-45/189.htm http://www.shop263.com/i-45/190.htm http://www.shop263.com/i-45/191.htm http://www.shop263.com/i-45/192.htm http://www.shop263.com/i-45/193.htm http://www.shop263.com/i-45/194.htm http://www.shop263.com/i-45/195.htm http://www.shop263.com/i-45/196.htm http://www.shop263.com/i-45/197.htm http://www.shop263.com/i-45/198.htm http://www.shop263.com/i-45/199.htm http://www.shop263.com/i-45/200.htm http://www.shop263.com/i-45/201.htm http://www.shop263.com/i-45/202.htm http://www.shop263.com/i-45/203.htm http://www.shop263.com/i-45/204.htm http://www.shop263.com/i-45/205.htm http://www.shop263.com/i-45/206.htm http://www.shop263.com/i-45/207.htm http://www.shop263.com/i-45/208.htm http://www.shop263.com/i-45/209.htm http://www.shop263.com/i-45/210.htm http://www.shop263.com/i-45/211.htm http://www.shop263.com/i-45/212.htm http://www.shop263.com/i-45/213.htm http://www.shop263.com/i-45/214.htm http://www.shop263.com/i-45/215.htm http://www.shop263.com/i-45/216.htm http://www.shop263.com/i-45/217.htm http://www.shop263.com/i-45/218.htm http://www.shop263.com/i-45/219.htm http://www.shop263.com/i-45/220.htm http://www.shop263.com/i-45/221.htm http://www.shop263.com/i-45/222.htm http://www.shop263.com/i-45/223.htm http://www.shop263.com/i-45/224.htm http://www.shop263.com/i-45/225.htm http://www.shop263.com/i-45/226.htm http://www.shop263.com/i-45/227.htm http://www.shop263.com/i-45/228.htm http://www.shop263.com/i-45/229.htm http://www.shop263.com/i-45/230.htm http://www.shop263.com/i-45/231.htm http://www.shop263.com/i-45/232.htm http://www.shop263.com/i-45/233.htm http://www.shop263.com/i-45/234.htm http://www.shop263.com/i-45/235.htm http://www.shop263.com/i-45/236.htm http://www.shop263.com/i-45/237.htm http://www.shop263.com/i-45/238.htm http://www.shop263.com/i-45/239.htm http://www.shop263.com/i-45/240.htm http://www.shop263.com/i-45/241.htm http://www.shop263.com/i-45/242.htm http://www.shop263.com/i-45/243.htm http://www.shop263.com/i-45/244.htm http://www.shop263.com/i-45/245.htm http://www.shop263.com/i-45/246.htm http://www.shop263.com/i-45/247.htm http://www.shop263.com/i-45/248.htm http://www.shop263.com/i-45/249.htm http://www.shop263.com/i-45/250.htm http://www.shop263.com/i-45/251.htm http://www.shop263.com/i-45/252.htm