Abstract: 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.

Abstract: An application (or process) may have an amount of steady state work to perform per unit time, as well as one or more mechanisms for doing a lower quality job of that work in the event the application falls behind. Approaches presented herein can utilize a clock monitor that enables the application to determine whether a clock loss was encountered that was due to an external source, and is of an amount of time that may be naturally recoverable by the application. If so, the application can enter into a mode of operation wherein the activation of one or more recovery mechanisms is postponed for a period of time to provide the application time to recover. If, after the period of such mode operation, the application has not recovered from the real time clock loss, then the recovery mechanism(s) can be activated as appropriate.

Abstract: A contribution encoder receives media from a source, encodes the media, and transmits the encoded media to a network-adaptive encoding system for eventual distribution to end users. The network-adaptive encoding system tests a network connection between the contribution encoder and the network-adaptive encoding system before transmission of the encoded media begins. The network-adaptive encoding system uses the results of the test to select appropriate values for parameters that define the encoding and transmission of the media. The selected parameter values are transmitted by the network-adaptive encoding system to the contribution encoder for use in encoding and transmitting the media.

Abstract: Technologies are provided for analyzing packet loss in network packet streams using windowed loss durations. A computing device can be configured to detect a first loss period in a network packet stream and a second, subsequent loss period in the network packet stream. The computing device can determine a number of packets received in the stream between the two loss periods, and can compare this number of packets to a specified recovery window length. If the number of packets received between the two loss periods is less than the recovery window length, then the computing device can treat the two loss periods, and the packets received between the two loss periods, as a single period of packet loss. The packet loss period can be treated as a single loss event for the purposes of analyzing network packet stream quality of experience and/or tuning packet loss compensation mechanisms.

Abstract: Systems and methods, to efficiently prepare for live and stored file content, implement one or more warm inputs, which actively ingest and demux content, but do not actively decode the content until an input switch is commanded. Each warm input can cache a most recent instantaneous decoder refresh and subsequent reference frames (I-frames and P-frames). Upon an input switch being commanded, the subject input commences decoding of such preserved frames. The formerly-warm input then acts as a hot input (decoding every frame) until the input switch completes. The use of warm inputs, which avoid the decoding stage, reduces computational resource use, allows preparation of all inputs by default, and permits metrics, status reports, and thumbnails to be generated regarding non-active inputs.

Abstract: Systems, devices, and methods are provided for transmitting and retransmitting data. A first message transmitted by a sender computing entity to a receiver computing entity over a first port may exercise a first network path whereas a second message transmitted over a second port may exercise a second network path. A system (e.g., sender computing entity) may determine network reliability metrics for a plurality of network paths. If a system detects data loss (e.g., packet loss) on a first port, a second port may be selected based on network reliability metrics for retransmission of the lost data. A port may for example, be selected for retransmission based on the following criteria: (1) the port has the longest consecutive duration without packet loss and (2) the port has received an acknowledgement for a packet that was sent more recently than the initial transmission of the lost packet.

Abstract: Techniques for adapting source ports for traffic include generating a first packet with a header and a payload, the header including an indication of a first source port from which the first packet is to be transmitted. The first packet is transmitted to a receiver using the first source port and, upon not receiving an acknowledgment from the receiver, a second packet with second header and the same payload is generated. The second header includes an indication of a second, different source port from which the second packet is to be transmitted. The second packet is transmitted to the receiver using the second, different source port. An acknowledgment is received from the receiver for one of the first or second packets, and the acknowledgment includes an indication of the source port that sent the packet.

Abstract: An application (or process) may have an amount of steady state work to perform per unit time, as well as one or more mechanisms for doing a lower quality job of that work in the event the application falls behind. Approaches presented herein can utilize a clock monitor that enables the application to determine whether a clock loss was encountered that was due to an external source, and is of an amount of time that may be naturally recoverable by the application. If so, the application can enter into a mode of operation wherein the activation of one or more recovery mechanisms is postponed for a period of time to provide the application time to recover. If, after the period of such mode operation, the application has not recovered from the real time clock loss, then the recovery mechanism(s) can be activated as appropriate.

Abstract: An application (or process) may have an amount of steady state work to perform per unit time, as well as one or more mechanisms for doing a lower quality job of that work in the event the application falls behind. Approaches presented herein can utilize a clock monitor that enables the application to determine whether a clock loss was encountered that was due to an external source, and is of an amount of time that may be naturally recoverable by the application. If so, the application can enter into a mode of operation wherein the activation of one or more recovery mechanisms is postponed for a period of time to provide the application time to recover. If, after the period of such mode operation, the application has not recovered from the real time clock loss, then the recovery mechanism(s) can be activated as appropriate.

Abstract: A content delivery service that facilitates the selection of virtual machine instances utilized to implement the transcoding function. A management service first implements a test channel configuration routine that selects worst case scenario configurations for implementing the transcoding function and measures performance metrics for different virtual machine instances implementing the transcoding function. The management system can then match incoming requests for video channel transcoding with signature data from the test channel configurations to identify which virtual machine instances can implement the requested transcoding functionality.

Abstract: Techniques for lossless transport stream compression from constant bitrate to variable bitrate to constant bitrate are described. An exemplary method includes generating elementary stream data from an encoder; receiving the generated elementary stream data in a packetizer; generating a transport stream output in the packetizer; and in a statmux, for consecutive NULL packets generated by the packetizer, counting a number of NULL packets between non-null packets and dropping those NULL packets, modifying a next packet to indicate the number of NULL packets dropped using a field in the next packet, and sending the next packet to a receiver.

Abstract: A content delivery service that facilitates the selection of virtual machine instances utilized to implement the transcoding function. A management service first implements a test channel configuration routine that selects worst case scenario configurations for implementing the transcoding function and measures performance metrics for different virtual machine instances implementing the transcoding function. The management system can then match incoming requests for video channel transcoding with signature data from the test channel configurations to identify which virtual machine instances can implement the requested transcoding functionality.

Abstract: Various embodiments of methods, apparatus, systems, and non-transitory computer-readable storage media for buffer recovery in segmented media delivery applications are described. Segments of a live media presentation are stored in a buffer. A number of segments in the buffer is determined to have fallen below a threshold. Based on that determination, various buffer recovery techniques may be performed. In one such technique, a buffered segment is decoded into a first set of video frames, the first set of video frames having a first playback duration. The first set of video frames is encoded into a second set of video frames having a second playback duration that is longer than the first playback duration.

Abstract: Techniques for using statmuxes are described.

Abstract: 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.

Abstract: Techniques for accommodating irregular timing information in streamed media data are described. According to some embodiments, at least a portion of a media stream that includes a video component is received, the video component including a plurality of video frames and video timing data, and wherein the media stream includes an indication of a video frame rate. A first duration of a first video frame of the plurality of video frames is determined to be different than an expected video frame duration, wherein the expected video frame duration is based at least in part on the indication of the video frame rate. A timestamp of at least one video frame of the plurality of video frames is adjusted to change the first duration.

Abstract: A content streaming system and methodology for facilitating the management of content streaming. A content delivery service receives streaming content that is encoded according to an encoding profile. The content delivery service decodes the received encoded content and encodes the decoded content according to a plurality of encoding profiles. Additionally, the content delivery service reuses the received encoded content stream from the content provider.

Abstract: Techniques for video with dynamic pixel update rates are described. A first video frame is received from a video source, the first video frame having a first pixel value at a first frame location of a plurality of frame locations, wherein the first frame location includes a horizontal pixel location and a vertical pixel location. A second video frame is received from the video source, the second video frame having a second pixel value at the first frame location. The first frame location is identified based at least in part on determining a difference between the first pixel value and the second pixel value. A package including a pixel update value and an indication of the first frame location is sent to a video destination, wherein the pixel update value is based at least in part on the second pixel value.

Abstract: A contribution encoder receives media from a source, encodes the media, and transmits the encoded media to a network-adaptive encoding system for eventual distribution to end users. The network-adaptive encoding system tests a network connection between the contribution encoder and the network-adaptive encoding system before transmission of the encoded media begins. The network-adaptive encoding system uses the results of the test to select appropriate values for parameters that define the encoding and transmission of the media. The selected parameter values are transmitted by the network-adaptive encoding system to the contribution encoder for use in encoding and transmitting the media.

Abstract: Media inputs, such as serial digital interface (SDI) inputs, can be concurrently monitored and ingested. An ingest process can be configured to concurrently monitor each of a set of SDI inputs. A transcoding job requiring content from one of the inputs can send a request over shared memory to the ingest process, which can copy the data to the media transcoding pipeline over shared memory while concurrently monitoring the SDI inputs. In at least some embodiments, multiple processes can concurrently ingest from a single SDI input.