From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.ffmpeg.org (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTPS id BA4B94BB8A for ; Wed, 23 Jul 2025 13:58:03 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTP id F1F2568D8D2; Wed, 23 Jul 2025 16:56:48 +0300 (EEST) Received: from haasn.dev (haasn.dev [78.46.187.166]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTP id 4A9FE68D887 for ; Wed, 23 Jul 2025 16:56:33 +0300 (EEST) Received: from haasn.dev (unknown [10.30.1.1]) by haasn.dev (Postfix) with UTF8SMTP id 7BF6C482D7; Wed, 23 Jul 2025 15:56:28 +0200 (CEST) From: Niklas Haas To: ffmpeg-devel@ffmpeg.org Date: Wed, 23 Jul 2025 15:47:11 +0200 Message-ID: <20250723135626.1390296-9-ffmpeg@haasn.xyz> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250723135626.1390296-1-ffmpeg@haasn.xyz> References: <20250723135626.1390296-1-ffmpeg@haasn.xyz> MIME-Version: 1.0 Subject: [FFmpeg-devel] [PATCH v2 08/18] avcodec/libjxl: set correct alpha mode X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Cc: Niklas Haas Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: From: Niklas Haas JPEG XL supports both premultiplied and straight alpha, and the basic info struct contains signalling for this. Forward the correct tagging on decode and encode. --- libavcodec/libjxldec.c | 6 ++++++ libavcodec/libjxlenc.c | 15 +++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/libavcodec/libjxldec.c b/libavcodec/libjxldec.c index 96c338d1b4..0c4091850c 100644 --- a/libavcodec/libjxldec.c +++ b/libavcodec/libjxldec.c @@ -433,6 +433,12 @@ static int libjxl_receive_frame(AVCodecContext *avctx, AVFrame *frame) if (ctx->basic_info.have_animation) ctx->anim_timebase = av_make_q(ctx->basic_info.animation.tps_denominator, ctx->basic_info.animation.tps_numerator); + if (ctx->basic_info.alpha_bits) { + if (ctx->basic_info.alpha_premultiplied) + avctx->alpha_mode = AVALPHA_MODE_PREMULTIPLIED; + else + avctx->alpha_mode = AVALPHA_MODE_STRAIGHT; + } continue; case JXL_DEC_COLOR_ENCODING: av_log(avctx, AV_LOG_DEBUG, "COLOR_ENCODING event emitted\n"); diff --git a/libavcodec/libjxlenc.c b/libavcodec/libjxlenc.c index 823abcafb8..924a835436 100644 --- a/libavcodec/libjxlenc.c +++ b/libavcodec/libjxlenc.c @@ -351,6 +351,15 @@ static int libjxl_preprocess_stream(AVCodecContext *avctx, const AVFrame *frame, jxl_fmt->data_type = info.bits_per_sample <= 8 ? JXL_TYPE_UINT8 : JXL_TYPE_UINT16; } + if (info.alpha_bits) { + if (avctx->alpha_mode == AVALPHA_MODE_PREMULTIPLIED || + avctx->alpha_mode == AVALPHA_MODE_UNSPECIFIED && frame->alpha_mode == AVALPHA_MODE_PREMULTIPLIED) { + info.alpha_premultiplied = 1; + } else if (avctx->alpha_mode != AVALPHA_MODE_STRAIGHT && frame->alpha_mode != AVALPHA_MODE_STRAIGHT) { + av_log(avctx, AV_LOG_WARNING, "Unknown alpha mode, assuming straight (independent)\n"); + } + } + #if JPEGXL_NUMERIC_VERSION >= JPEGXL_COMPUTE_NUMERIC_VERSION(0, 8, 0) jxl_bit_depth.bits_per_sample = bits_per_sample; jxl_bit_depth.type = JXL_BIT_DEPTH_FROM_PIXEL_FORMAT; @@ -713,6 +722,9 @@ const FFCodec ff_libjxl_encoder = { FF_CODEC_CAP_AUTO_THREADS | FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_ICC_PROFILES, CODEC_PIXFMTS_ARRAY(libjxl_supported_pixfmts), + .alpha_modes = (const enum AVAlphaMode[]) { + AVALPHA_MODE_STRAIGHT, AVALPHA_MODE_PREMULTIPLIED, AVALPHA_MODE_UNSPECIFIED + }, .p.priv_class = &libjxl_encode_class, .p.wrapper_name = "libjxl", }; @@ -733,6 +745,9 @@ const FFCodec ff_libjxl_anim_encoder = { FF_CODEC_CAP_AUTO_THREADS | FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_ICC_PROFILES, CODEC_PIXFMTS_ARRAY(libjxl_supported_pixfmts), + .alpha_modes = (const enum AVAlphaMode[]) { + AVALPHA_MODE_STRAIGHT, AVALPHA_MODE_PREMULTIPLIED, AVALPHA_MODE_UNSPECIFIED + }, .p.priv_class = &libjxl_encode_class, .p.wrapper_name = "libjxl", }; -- 2.50.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".