Amazon Technologies, Inc.

Trevor Wells

Ryan Paul Hegar

Brian Lewis

Jeffrey K Lassahn

David Montgomery

Max C Denton

Colin McCoy

Kevin Moore

Erik Jason Johnson

John Bach

Ai Luo

Brandon Lin

Krishna Sankaran

Jordan Gilman

Approaches provided herein can provide for adjustments to audio data. In particular, an audio resampling process can be performed wherein the correct audio frame size is determined. A 'target' audio stream duration, as may be indicated by a time-to-sample atom (STTS) atom, can be used to apply one or more pitch-invariant, time-stretching audio filters to the audio data as that data is decoded during a media transcode process. A resulting output media metadata can specify accurate, constant audio frame durations, and the audio stream duration can match the corresponding video stream duration in a media file.

Audio resampling for media synchronization

A transcoding process may be performed in parallel, which may include different nodes processing different segments of a media file at different times. Different time slices of media files may have different properties, which may lead to errors when media files are encoded for later playback. Extracting metadata from frames of media files and evaluating the frames for discrepancies enables creation of a reconciliation manifest to correct discrepancies associated with the media file. As the transcoding process is performed, the reconciliation manifest may be reference to generate an output media file.

Reconciliation for parallel transcoding

Various embodiments of an automated adaptive bitrate ('ABR') encoding system and method that encodes an input video into a set of encoded video streams for ABR delivery, also known as an ABR ladder. The automated ABR encoding system encodes the input video into an initial number of speculative encodings, based on respectively determined resolution and quality level settings for the individual speculative encodings. It then estimates quality scores for a plurality of potential output encodings based on respective output statistics of the speculative encodings. It selects a plurality of better quality output encodings from the plurality of potential output encodings based on the quality scores. It then encodes the input video a second time into the plurality of better quality output encodings. The automated ABR encoding system selects one or more output encodings from the plurality of better quality output encodings to include in the ABR ladder.

Automated adaptive bitrate encoding

Techniques for dynamic video bandwidth determination are described. An exemplary method includes receiving an indication of a desired total bitrate for a multiple program transport stream (MPTS), the MPTS having at least two programs; receiving non-video content from two or more encoders; buffering video content during a determination of available video bandwidth; and determining an amount of the desired total bitrate to be the available video bandwidth by: for each active encoder, determining a non-video bitrate over a first time period for each encoder using a sliding window based on a statistical measurement, summing the determined non-video bitrates for the active encoders to get a total non-video bitrate, subtracting the total non-video bitrate from the desired total bitrate to get an available video bandwidth, and allocating the available video bandwidth amongst the two or more encoders.

Dynamic statmux video bandwidth determination

Methods, systems, and computer-readable media for real-time video streaming with latency control are disclosed. Using a media streaming system, a current frame of a video input is acquired from an input pipeline. The current frame is associated with a timestamp. A mapped timestamp associated with the current frame is determined. The mapped timestamp represents the timestamp mapped to a clock associated with the media streaming system. Based at least in part on a comparison between the mapped timestamp and a deadline for frame output, the current frame is either transmitted to an output pipeline according to the deadline, held for evaluation against one or more subsequent deadlines, or discarded.

Real-time video streaming with latency control

Methods, systems, and computer-readable media for bitrate allocation for a multichannel media stream are disclosed. Complexity values are determined for individual channels of a set of channels of a multichannel media stream. The complexity values are determined based (at least in part) on frames of the individual channels during a window of time. The multichannel media stream is associated with a maximum aggregate bitrate, and the individual channels are associated with minimum individual bitrates and maximum individual bitrates. Individual bitrates are determined for the individual channels based (at least in part) on the complexity values. The sum of the individual bitrates does not exceed the maximum aggregate bitrate beyond a predetermined threshold, and the individual bitrates fall between the minimum and maximum individual bitrates of the corresponding individual channels. The individual channels are encoded at bitrates approximating the corresponding individual bitrates and transmitted to one or more recipients.

Bitrate allocation for a multichannel media stream

An encoding or transcoding system uses hypothetical reference decoder occupancy data to at least calculate parameters for output buffers for data streams. An output thread receives HRD buffer occupancy data and calculates buffer occupancy based on duration, rather than absolute occupancy, and correlates the HRD buffer occupancy data with target durations for buffered packets prior to release from the buffer.

Encoder-sensitive stream buffer management

Pre-roll markers are encoded into media content at determined locations to provide a specified amount of pre-roll time before supplemental content is to be provided in place of the primary content of the media file. The supplemental content can be any appropriate content, as may relate to promotional or information content relevant in some way to the primary content or a viewer of the primary content. A marker such as a SCTE-104 message can be received with the media input and translated to a SCTE-35 message during the encoding process. The video stream can be buffered by an amount corresponding to a determined pull-up time such that the SCTE-35 marker, when received to the multiplexer, can be placed into the transport stream at the appropriate location. When received, the marker can provide sufficient notice to prepare the supplemental content to be displayed at the injection point.

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Washougal, WA, United States of America

Trevor Wells