Netflix Inc.

David Randall Ronca

Yung-Hsiao Lai

James Mitch Zollinger

Chung-Ping Wu

Christian Kaiser

Ioannis Katsavounidis

Anne Aaron

Andy Schuler

Anthony Neal Park

Dae Kim

Kay Neuenhofen

Yu-Chieh Lin

Kuyen Tsao

Chi-Hao Wu

Steven Kang

Rama Kalluri

Scott Gregory Kelly

Techniques are disclosed for multiplexing a dynamic bit-rate video stream with an audio stream received by a client device in a manner that allows the resulting multiplexed stream to be played back without disruption, despite dynamic changes in the bit rate of the video stream that may occur. A content server may stream both a video stream and an audio stream to a client device for playback. The client device may multiplex the video and audio streams prior to them being presented to a playback engine for decoding and playback to a user.

On-device multiplexing of streaming media content

In one embodiment of the present invention, a quality trainer and quality calculator collaborate to establish a consistent perceptual quality metric via machine learning. In a training phase, the quality trainer leverages machine intelligence techniques to create a perceptual quality model that combines objective metrics to optimally track a subjective metric assigned during viewings of training videos. Subsequently, the quality calculator applies the perceptual quality model to values for the objective metrics for a target video, thereby generating a perceptual quality score for the target video. In this fashion, the perceptual quality model judiciously fuses the objective metrics for the target video based on the visual feedback processed during the training phase. Since the contribution of each objective metric to the perceptual quality score is determined based on empirical data, the perceptual quality score is a more accurate assessment of observed video quality than conventional objective metrics.

Techniques for predicting perceptual video quality

In one embodiment of the present invention, an encoding bitrate ladder selector tailors bitrate ladders to the complexity of source data. Upon receiving source data, a complexity analyzer configures an encoder to repeatedly encode the source data-setting a constant quantization parameter to a different value for each encode. The complexity analyzer processes the encoding results to determine an equation that relates a visual quality metric to an encoding bitrate. The bucketing unit solves this equation to estimate a bucketing bitrate at a predetermined value of the visual quality metric. Based on the bucketing bitrate, the bucketing unit assigns the source data to a complexity bucket having an associated, predetermined bitrate ladder. Advantageously, sagaciously selecting the bitrate ladder enables encoding that optimally reflects tradeoffs between quality and resources (e.g., storage and bandwidth) across a variety of source data types instead of a single, 'typical' source data type.

Techniques for optimizing bitrates and resolutions during encoding

Embodiments for changing bit rates in streaming media are provided. As portions of a streaming media file are downloaded for playback, the size of the portion is compared with an expected size determined prior to initiating playback of streaming AV data. The portion of the media file may be padded such that the size of the portion matches the size specified prior to initiating playback of streaming AV data.

Bit rate stream switching

Techniques are disclosed for a client device to stream a user-selected media file from a content server. The client device may create a playlist of dynamic virtual chunks to represent a single media stream file on a streaming media server. The playlist itself may be generated from an index in the header of a given stream defining what chunks, or segments of multiplexed audiovisual content, are present within that stream. The playlist of dynamic virtual chunks provides the playback engine on the client device with a list of individual files that may be requested from the streaming server independently of one another, despite the stream being stored on the server as a single media stream file.

Dynamic virtual chunking of streaming media content

Embodiments of the invention provide techniques for encoding chunks of a video file in parallel. Embodiments may divide a source video file into a plurality of chunks, and may encode each chunk at a rate based upon complexity data associated with the chunk. The encoded chunks may then be reassembled to produce an encoded video file.

Parallel video encoding based on complexity analysis

One embodiment of the present invention sets forth a technique for decrypting digital content in a secure environment. The technique includes the steps of receiving a digital rights management (DRM) license associated with a first frame of encrypted data from a DRM server, where the DRM license includes a decryption key for decrypting the first frame of encrypted data, transmitting the DRM license to a secure content playback pipeline for storage, and transmitting the first frame of encrypted data to the secure content playback pipeline for decryption, where, in response to receiving the first frame of encrypted data, a trusted processing entity within the secure content playback pipeline decrypts the first frame of encrypted data based on the decryption key included in the DRM license to generate a first set of decrypted data and store the first set of decrypted data in a secure memory space.

Content playback APIS using encrypted streams

One embodiment of the invention sets forth an encoding server including components configured to encode a video stream associated with a content title for adaptive streaming. The video stream is first processed by a VC1 encoder to generate an encoded video stream comprising a multiple GOPs, each GOP including a key frame and having a different playback offset. The encoded video stream is then packaged such that the GOPs are stored in data packets of the packaged encoded stream. An SHI generator generates an SHI associated with the packaged encoded stream that includes a switch point associated with each GOP. Each switch point includes the playback offset associated with the corresponding GOP and the data packet storing the key frame of the corresponding GOP. The SHI associated with multiple packaged encoded video streams associated with the same content title and encoded to different playback bit rates have corresponding switch points.

Growing community of inventors

Campbell, CA, United States of America

David Randall Ronca