From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTPS id 018D644D6B for ; Sat, 18 Jan 2025 22:51:02 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id D20DB68B1AC; Sun, 19 Jan 2025 00:50:58 +0200 (EET) Received: from relay8-d.mail.gandi.net (relay8-d.mail.gandi.net [217.70.183.201]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 01A8268AD89 for ; Sun, 19 Jan 2025 00:50:51 +0200 (EET) Received: by mail.gandi.net (Postfix) with ESMTPSA id 1FF8F1BF203 for ; Sat, 18 Jan 2025 22:50:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=niedermayer.cc; s=gm1; t=1737240651; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=Iriqt7iRJVgA8O2WPfij82u+SRX9rFyEHZZwgQE7ZBo=; b=epqjah6XMDSJHS/IxJCefmg6HtDttZPy7uYTM9KqYk0irN7JMsnmHoq1KWdIlOVEDvjMRM TzgaVUbl1d6/2FHrkXYpdP8YXw+MZf8jPh3fWbxlmD1M1bJ4FcpzvhaptzPk6u5M6/UUZZ X6N3ahNOuOe8hJutslupzJqz8hzJFfSyAQLcb5ZDQAyFcP/TCbf44vpeSulpyemYOehxpi Exd1OSyuubvOocZQsIECD6QK/E/PpaTWy2tAlBwGvNro/WB+pV2i4VFfuEYvsk4p/7oomV A8iXFUC1NheVaS4JKAU3QWG2yC+y7gDDcT4OICUd3XpH1CiUkTquj3L3DGLLTQ== From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Sat, 18 Jan 2025 23:50:49 +0100 Message-ID: <20250118225050.2935283-1-michael@niedermayer.cc> X-Mailer: git-send-email 2.48.1 MIME-Version: 1.0 X-GND-Sasl: michael@niedermayer.cc Subject: [FFmpeg-devel] [PATCH 1/2] avcodec/ffv1: flip half of float16 and Compactify floats 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 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: float16 (and more so float32) have many odd values half the values are negative, many are larger than "1.0" and many values are very close to 0. Storing the 16bits as is, looses compression because of the mixture of dense and sparse regions and also many completely unused ones. This simply remaps the 65536 values so no unused values remain This improves compression by about 1.5% for the ACES_OT_VWG_SampleFrames testset (this testset contains all kind of funny values including many images with negative rgb values) The space needed for the map is insignificant compared to the compression gained This patch also flips half the float range as it can be done using the same table. Sponsored-by: Sovereign Tech Fund Signed-off-by: Michael Niedermayer --- libavcodec/ffv1.h | 1 + libavcodec/ffv1dec_template.c | 21 +++++++++++++++ libavcodec/ffv1enc_template.c | 49 +++++++++++++++++++++++++++++++++++ 3 files changed, 71 insertions(+) diff --git a/libavcodec/ffv1.h b/libavcodec/ffv1.h index 2c2df154037..bf49f613a75 100644 --- a/libavcodec/ffv1.h +++ b/libavcodec/ffv1.h @@ -104,6 +104,7 @@ typedef struct FFV1SliceContext { uint64_t (*rc_stat2[MAX_QUANT_TABLES])[32][2]; }; }; + uint16_t fltmap[4][65536]; } FFV1SliceContext; typedef struct FFV1Context { diff --git a/libavcodec/ffv1dec_template.c b/libavcodec/ffv1dec_template.c index e983d1ba648..a419aca8584 100644 --- a/libavcodec/ffv1dec_template.c +++ b/libavcodec/ffv1dec_template.c @@ -155,6 +155,20 @@ static int RENAME(decode_rgb_frame)(FFV1Context *f, FFV1SliceContext *sc, memset(RENAME(sc->sample_buffer), 0, 8 * (w + 6) * sizeof(*RENAME(sc->sample_buffer))); + if (f->flt) { + for (int p= 0; p<3 + transparency; p++) { + int j = 0; + int lu = 0; + uint8_t state[2] = {128, 128}; + for (int i= 0; i<65536; i++) { + int u = get_rac(&sc->c, state + lu); + sc->fltmap[p][j] = i ^ ((i&0x8000) ? 0 : 0x7FFF); + j+= u; + lu = u; + } + } + } + for (y = 0; y < h; y++) { for (p = 0; p < 3 + transparency; p++) { int ret; @@ -185,6 +199,13 @@ static int RENAME(decode_rgb_frame)(FFV1Context *f, FFV1SliceContext *sc, b += g; r += g; } + if (f->flt) { + r = sc->fltmap[0][r]; + g = sc->fltmap[1][g]; + b = sc->fltmap[2][b]; + if (transparency) + a = sc->fltmap[3][a]; + } if (lbd) *((uint32_t*)(src[0] + x*4 + stride[0]*y)) = b + ((unsigned)g<<8) + ((unsigned)r<<16) + ((unsigned)a<<24); diff --git a/libavcodec/ffv1enc_template.c b/libavcodec/ffv1enc_template.c index bc14926ab95..0d1b0a28432 100644 --- a/libavcodec/ffv1enc_template.c +++ b/libavcodec/ffv1enc_template.c @@ -148,6 +148,47 @@ static int RENAME(encode_rgb_frame)(FFV1Context *f, FFV1SliceContext *sc, memset(RENAME(sc->sample_buffer), 0, ring_size * MAX_PLANES * (w + 6) * sizeof(*RENAME(sc->sample_buffer))); + if (f->flt) { + memset(sc->fltmap, 0, sizeof(sc->fltmap)); + + for (y = 0; y < h; y++) { + for (x = 0; x < w; x++) { + int b, g, r, av_uninit(a); + + if (sizeof(TYPE) == 4 || transparency) { + g = *((const uint16_t *)(src[0] + x*2 + stride[0]*y)); + b = *((const uint16_t *)(src[1] + x*2 + stride[1]*y)); + r = *((const uint16_t *)(src[2] + x*2 + stride[2]*y)); + if (transparency) + a = *((const uint16_t *)(src[3] + x*2 + stride[3]*y)); + } else { + b = *((const uint16_t *)(src[0] + x*2 + stride[0]*y)); + g = *((const uint16_t *)(src[1] + x*2 + stride[1]*y)); + r = *((const uint16_t *)(src[2] + x*2 + stride[2]*y)); + } + + sc->fltmap[0][r] = 1; + sc->fltmap[1][g] = 1; + sc->fltmap[2][b] = 1; + if (transparency) + sc->fltmap[3][a] = 1; + } + } + for (int p= 0; p<3 + transparency; p++) { + int j = 0; + int lu = 0; + uint8_t state[2] = {128, 128}; + for (int i= 0; i<65536; i++) { + int ri = i ^ ((i&0x8000) ? 0 : 0x7FFF); + int u = sc->fltmap[p][ri]; + sc->fltmap[p][ri] = j; + j+= u; + put_rac(&sc->c, state + lu, u); + lu = u; + } + } + } + for (y = 0; y < h; y++) { for (i = 0; i < ring_size; i++) for (p = 0; p < MAX_PLANES; p++) @@ -180,6 +221,14 @@ static int RENAME(encode_rgb_frame)(FFV1Context *f, FFV1SliceContext *sc, r = *((const uint16_t *)(src[2] + x*2 + stride[2]*y)); } + if (f->flt) { + r = sc->fltmap[0][r]; + g = sc->fltmap[1][g]; + b = sc->fltmap[2][b]; + if (transparency) + a = sc->fltmap[3][a]; + } + if (sc->slice_coding_mode != 1) { b -= g; r -= g; -- 2.48.1 _______________________________________________ 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".