Hi I needed the dynamic resolution changing feature of NVENC to be accessible through the ffmpeg libraries for a hobby project, so I added support and here is a patch.
I will format this as a proper patch after any changes necessary following feedback. To use this feature you would need to: 1. Specify max_width and max_height before opening the encoder 2. Change the encoder context width/height during encoding Note that it is the caller's responsibility to scale the input frames to match the new encoder size after changing it! In my test I just use sws_scale where needed. Here is a link to a file that switches resolution a few times between 1920x1080 and 1280x720, that was generated using this patch. This plays correctly in VLC. https://www.dropbox.com/s/rvt94ai3jx5lbi9/test_switching_2.ts?dl=0 <https://www.dropbox.com/s/rvt94ai3jx5lbi9/test_switching_2.ts?dl=0> Regards Oliver diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h index 0ce22ec4fa..7087f82ce1 100644 --- a/libavcodec/avcodec.h +++ b/libavcodec/avcodec.h @@ -3357,6 +3357,12 @@ typedef struct AVCodecContext { * - encoding: unused */ int discard_damaged_percentage; + + /* + * Video encoding only. Sets the maximum picture size for encoders that + * support adjusting the picture size dynamically during encoding. + */ + int max_width, max_height; } AVCodecContext; #if FF_API_CODEC_GET_SET diff --git a/libavcodec/nvenc.c b/libavcodec/nvenc.c index 304a684e0c..414707dcfd 100644 --- a/libavcodec/nvenc.c +++ b/libavcodec/nvenc.c @@ -384,6 +384,7 @@ static int nvenc_check_capabilities(AVCodecContext *avctx) #endif ctx->support_dyn_bitrate = nvenc_check_cap(avctx, NV_ENC_CAPS_SUPPORT_DYN_BITRATE_CHANGE); + ctx->support_dyn_res = nvenc_check_cap(avctx, NV_ENC_CAPS_SUPPORT_DYN_RES_CHANGE); return 0; } @@ -1121,6 +1122,8 @@ static av_cold int nvenc_setup_encoder(AVCodecContext *avctx) ctx->init_encode_params.encodeHeight = avctx->height; ctx->init_encode_params.encodeWidth = avctx->width; + ctx->init_encode_params.maxEncodeHeight = avctx->max_height; + ctx->init_encode_params.maxEncodeWidth = avctx->max_width; ctx->init_encode_params.encodeConfig = &ctx->encode_config; @@ -1276,8 +1279,8 @@ static av_cold int nvenc_alloc_surface(AVCodecContext *avctx, int idx) } allocSurf.version = NV_ENC_CREATE_INPUT_BUFFER_VER; - allocSurf.width = avctx->width; - allocSurf.height = avctx->height; + allocSurf.width = FFMAX(avctx->max_width, avctx->width); + allocSurf.height = FFMAX(avctx->max_height, avctx->height); allocSurf.bufferFmt = ctx->surfaces[idx].format; nv_status = p_nvenc->nvEncCreateInputBuffer(ctx->nvencoder, &allocSurf); @@ -1926,7 +1929,7 @@ static void reconfig_encoder(AVCodecContext *avctx, const AVFrame *frame) NV_ENC_RECONFIGURE_PARAMS params = { 0 }; int needs_reconfig = 0; int needs_encode_config = 0; - int reconfig_bitrate = 0, reconfig_dar = 0; + int reconfig_bitrate = 0, reconfig_dar = 0, reconfig_res = 0; int dw, dh; params.version = NV_ENC_RECONFIGURE_PARAMS_VER; @@ -1986,6 +1989,24 @@ static void reconfig_encoder(AVCodecContext *avctx, const AVFrame *frame) } } + if (ctx->support_dyn_res && ctx->init_encode_params.maxEncodeWidth && ctx->init_encode_params.maxEncodeHeight) { + if (params.reInitEncodeParams.encodeWidth != avctx->width || params.reInitEncodeParams.encodeHeight != avctx->height) { + av_log(avctx, AV_LOG_VERBOSE, + "resolution change: %d x %d -> %d x %d\n", + params.reInitEncodeParams.encodeWidth, + params.reInitEncodeParams.encodeHeight, + (uint32_t)avctx->width, + (uint32_t)avctx->height); + + params.reInitEncodeParams.encodeWidth = avctx->width; + params.reInitEncodeParams.encodeHeight = avctx->height; + params.forceIDR = 1; + + needs_reconfig = 1; + reconfig_res = 1; + } + } + if (!needs_encode_config) params.reInitEncodeParams.encodeConfig = NULL; @@ -2005,6 +2026,10 @@ static void reconfig_encoder(AVCodecContext *avctx, const AVFrame *frame) ctx->encode_config.rcParams.vbvBufferSize = params.reInitEncodeParams.encodeConfig->rcParams.vbvBufferSize; } + if (reconfig_res) { + ctx->init_encode_params.encodeWidth = params.reInitEncodeParams.encodeWidth; + ctx->init_encode_params.encodeHeight = params.reInitEncodeParams.encodeHeight; + } } } } diff --git a/libavcodec/nvenc.h b/libavcodec/nvenc.h index ddd6168409..f3b959b31a 100644 --- a/libavcodec/nvenc.h +++ b/libavcodec/nvenc.h @@ -158,6 +158,7 @@ typedef struct NvencContext int first_packet_output; int support_dyn_bitrate; + int support_dyn_res; void *nvencoder; diff --git a/libavcodec/version.h b/libavcodec/version.h index 309e4111cb..a217283b03 100644 --- a/libavcodec/version.h +++ b/libavcodec/version.h @@ -29,7 +29,7 @@ #define LIBAVCODEC_VERSION_MAJOR 58 #define LIBAVCODEC_VERSION_MINOR 47 -#define LIBAVCODEC_VERSION_MICRO 103 +#define LIBAVCODEC_VERSION_MICRO 104 #define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \ LIBAVCODEC_VERSION_MINOR, \ _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel