# US 2020/0404288 A1 · Preserving image quality in temporally compressed video streams > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0404288 A1 - Document ID: US20200404288A1 - Status: Published application - Kind: A1 - Application number: 16/921,377 - Filed: 2020-07-06 - Published: 2020-12-24 - Earliest claimed: 2011-07-14 - Assignees: Comcast Cable Communications, LLC - Applicants: Comcast Cable Communications, LLC - Inventors: Yasser F. Syed - Web page: https://patentgrep.com/patent/US20200404288A1 ## CPC - H04N 19/159: Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction - H04N 19/154: Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion (use of rate-distortion criteria H04N19/147) - H04N 19/167: Position within a video image, e.g. region of interest [ROI] - H04N 19/40: using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract When a temporally compressed video stream is decoded and subsequently re-encoded, quality is typically lost. The quality loss may be mitigated using information about how the source video stream was encoded during the re-encoding process. According to some aspects of the disclosure, this mitigation of quality loss can be facilitated by decoders that output such information and encoders that receive such information. These decoders and encoders may be separate devices. The functionality of these decoders and encoders may also be combined in a single device, such as a transcoding device. An example of the information that may be used during re-encoding is whether each portion of the original stream was intra-coded or non-intra-coded. ## Claims ### Claim 1 A method comprising: decoding, by a computing device, a first encoded video stream to generate: a decoded video stream, and first data indicating: a first set of regions that are intra-coded in the first encoded video stream; and a second set of regions that are bi-predictive-coded in the first encoded video stream and that are selected based on a first format of the first encoded video stream; and encoding, using the first data, the decoded video stream into a second encoded video stream, wherein the first set of regions and the second set of regions are encoded into intra-coded regions in the second encoded video stream. ### Claim 2 (depends on 1) The method of claim 1, wherein the second encoded video stream is encoded in a second format different from the first format. ### Claim 3 (depends on 1) The method of claim 1, wherein the first data further indicates a third set of regions that are intra-coded in the first encoded video stream, and wherein the encoding comprises encoding the third set of regions into non-intra-coded regions in the second encoded video stream, wherein the third set of regions is encoded with less spatial compression than other regions in the second encoded video stream. ### Claim 4 (depends on 1) The method of claim 1, wherein the second set of regions are selected based on a determination that the first format does not encode predictive-coded regions with less quality loss than bi-predictive regions. ### Claim 5 (depends on 1) The method of claim 1, wherein the first data further indicates a third set of regions that are non-intra coded in the first encoded video stream and that are selected based on a target quality for the second encoded video stream, wherein the target quality comprises a target for an amount of space required to store the second encoded video stream or a target average distance between intra-coded regions in the second encoded video stream, and wherein the encoding comprises encoding the third set of regions into intra-coded regions in the second encoded video stream. ### Claim 6 (depends on 1) The method of claim 1, wherein the first data further indicates a third set of regions that are predictive-coded in the first encoded video stream and that are to be predictive-coded in the second encoded video stream; and wherein the encoding comprises encoding the third set of regions into predictive-coded regions in the second encoded video stream. ### Claim 7 (depends on 6) The method of claim 6, wherein the third set of regions are selected based on a determination that a second format, into which the second encoded video stream is to be encoded, encodes predictive-coded regions with less quality loss than bi-predictive regions. ### Claim 8 A method comprising: receiving, by a computing device, a first encoded video stream; determining a first set of regions, from the first encoded video stream, to intra-code in a second encoded video stream, wherein the first set of regions are intra-coded in the first encoded video stream; determining a non-intra-coded region, from the first encoded video stream, to intra-code as an instantaneous decoding refresh (IDR) region in the second encoded video stream, wherein the non-intra-coded region is determined based on a determination that, in the second encoded video stream, the non-intra-coded region does not reference regions prior to the non-intra-coded region; and transcoding the first encoded video stream to the second encoded video stream, wherein the transcoding comprises transcoding the first set of regions into intra-coded regions in the second encoded video stream and transcoding the non-intra-coded region into the IDR region in the second encoded video stream. ### Claim 9 (depends on 8) The method of claim 8, further comprising: receiving data associated with the first encoded video stream, wherein determining the non-intra-coded region to intra-code as the IDR region comprises: determining, based on the data indicating the non-intra-coded region to intra-code as the IDR region, the non-intra-coded region. ### Claim 10 (depends on 8) The method of claim 8, further comprising: receiving data indicating a point between a first region and a second region in the first encoded video stream at which a video stream is to be inserted in the second encoded video stream during the transcoding, wherein determining the non-intra-coded region to intra-code as the IDR region comprises: determining the second region as the non-intra-coded region to intra-code as the IDR region, wherein, in the first encoded video stream, the second region follows the point. ### Claim 11 (depends on 8) The method of claim 8, further comprising: determining an additional set of regions, from the first encoded video stream, to intra-code in the second encoded video stream, wherein the additional set of regions is determined based on a determination that non-intra-coding the additional set of regions in the second encoded video stream would result in greater than a threshold amount of quality loss for the additional set of regions. ### Claim 12 (depends on 8) The method of claim 8, further comprising: determining an additional set of regions, from the first encoded video stream, to intra-code in the second encoded video stream, wherein the additional set of regions is determined based on a determination that non-intra-coding the additional set of regions in the second encoded video stream would require an amount of space greater than required for intra-coding the additional set of regions in the second encoded video stream. ### Claim 13 (depends on 8) The method of claim 8, wherein the first set of regions are determined based on a target quality for the second encoded video stream, wherein the target quality comprises a target for an amount of space required to store the second encoded video stream or a target average distance between intra-coded regions in the second encoded video stream. ### Claim 14 (depends on 8) The method of claim 8, further comprising: determining a target average distance between intra-coded regions in the second encoded video stream; and determining an additional set of regions, from the first encoded video stream, to intra-code in the second encoded video stream, wherein the first set of regions to intra-code in the second encoded video stream are determined based on the target average distance between intra-coded regions, and wherein the additional set of regions to intra-code in the second encoded video stream are excluded from the target average distance between intra-coded regions. ### Claim 15 A method comprising: transmitting, by a server, to a computing device, and via a network, a first portion of content, wherein the content is encoded in a first format; determining, during transmission of the first portion of the content, a change in available bandwidth on the network; transcoding, based on determining the change in the available bandwidth, a second portion of the content to a new content encoded in a second format, wherein the transcoding comprises: selecting, from the second portion of the content and based on a target percentage of instantaneous decoding refresh (IDR) regions to transcode into IDR regions in the new content, one or more IDR regions; and transcoding the one or more IDR regions into IDR regions in the second format in the new content; and transmitting, to the computing device, the new content in the second format. ### Claim 16 (depends on 15) The method of claim 15, wherein the transcoding further comprises selecting, from the second portion of the content and based on the first format of the content, one or more predictive-coded regions; and transcoding the one or more predictive-coded regions into intra-coded regions in the second format in the new content. ### Claim 17 (depends on 16) The method of claim 16, wherein the one or more predictive-coded regions are selected based on a determination that the first format encodes predictive-coded regions with less quality loss than bi-predictive regions. ### Claim 18 (depends on 15) The method of claim 15, wherein versions of the content, in a plurality of different formats, are stored, and wherein the method further comprises: determining a version of the content having a highest quality; and retrieving the second portion of the content from the version of the content having the highest quality. ### Claim 19 (depends on 15) The method of claim 15, wherein the first format is a higher bandwidth format than the second format. ### Claim 20 (depends on 15) The method of claim 15, wherein the server comprises a multiple bitrate streaming server.