diff --git a/MAINTAINERS b/MAINTAINERS
index 931cf4bd2c..2e0de9e224 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -188,6 +188,7 @@ Codecs:
   interplayvideo.c                      Mike Melanson
   jni*, ffjni*                          Matthieu Bouron
   jpeg2000*                             Nicolas Bertrand
+  jpegxl.h, jpegxl_parser.c             Leo Izen
   jvdec.c                               Peter Ross
   lcl*.c                                Roberto Togni, Reimar Doeffinger
   libcelt_dec.c                         Nicolas George
@@ -616,6 +617,7 @@ Haihao Xiang (haihao)         1F0C 31E8 B4FE F7A4 4DC1 DC99 E0F5 76D4 76FC 437F
 Jaikrishnan Menon             61A1 F09F 01C9 2D45 78E1 C862 25DC 8831 AF70 D368
 James Almer                   7751 2E8C FD94 A169 57E6 9A7A 1463 01AD 7376 59E0
 Jean Delvare                  7CA6 9F44 60F1 BDC4 1FD2 C858 A552 6B9B B3CD 4E6A
+Leo Izen (thebombzen)         B6FD 3CFC 7ACF 83FC 9137 6945 5A71 C331 FD2F A19A
 Loren Merritt                 ABD9 08F4 C920 3F65 D8BE 35D7 1540 DAA7 060F 56DE
 Lynne                         FE50 139C 6805 72CA FD52 1F8D A2FE A5F0 3F03 4464
 Michael Niedermayer           9FF2 128B 147E F673 0BAD F133 611E C787 040B 0FAB
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index fb8b0e824b..3723601b3d 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -44,6 +44,7 @@ OBJS = ac3_parser.o                                                     \
        dv_profile.o                                                     \
        encode.o                                                         \
        imgconvert.o                                                     \
+       jpegxl_parser.o                                                  \
        jni.o                                                            \
        mathtables.o                                                     \
        mediacodec.o                                                     \
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index 81f3b3c640..1b82870aaa 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -1863,6 +1863,15 @@ static const AVCodecDescriptor codec_descriptors[] = {
         .long_name = NULL_IF_CONFIG_SMALL("GEM Raster image"),
         .props     = AV_CODEC_PROP_LOSSY,
     },
+    {
+        .id        = AV_CODEC_ID_JPEGXL,
+        .type      = AVMEDIA_TYPE_VIDEO,
+        .name      = "jpegxl",
+        .long_name = NULL_IF_CONFIG_SMALL("JPEG XL"),
+        .props     = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSY |
+                     AV_CODEC_PROP_LOSSLESS,
+        .mime_types= MT("image/jxl"),
+    },
 
     /* various PCM "codecs" */
     {
diff --git a/libavcodec/codec_id.h b/libavcodec/codec_id.h
index 3ffb9bd22e..dbc4f3a208 100644
--- a/libavcodec/codec_id.h
+++ b/libavcodec/codec_id.h
@@ -308,6 +308,7 @@ enum AVCodecID {
     AV_CODEC_ID_SIMBIOSIS_IMX,
     AV_CODEC_ID_SGA_VIDEO,
     AV_CODEC_ID_GEM,
+    AV_CODEC_ID_JPEGXL,
 
     /* various PCM "codecs" */
     AV_CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the start of audio codecs
diff --git a/libavcodec/jpegxl.h b/libavcodec/jpegxl.h
new file mode 100644
index 0000000000..4f93c99687
--- /dev/null
+++ b/libavcodec/jpegxl.h
@@ -0,0 +1,43 @@
+/*
+ * JPEG XL header
+ * Copyright (c) 2021 Leo Izen <leo.izen@gmail.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * JPEG XL header
+ */
+
+#ifndef AVCODEC_JPEGXL_H
+#define AVCODEC_JPEGXL_H
+
+#include <stdint.h>
+
+/* these are also used in avformat/img2dec.c */
+#define FF_JPEGXL_CODESTREAM_SIGNATURE_LE 0x0aff
+#define FF_JPEGXL_CODESTREAM_SIGNATURE_BE 0xff0a
+#define FF_JPEGXL_CONTAINER_SIGNATURE_LE 0x204c584a0c000000
+#define FF_JPEGXL_CONTAINER_SIGNATURE_BE 0x0000000c4a584c20
+
+/**
+ * @return 0 upon valid, nonzero upon some parse error
+ */
+int avpriv_jpegxl_verify_codestream_header(void *avctx, uint8_t *buf, int buflen);
+
+#endif /* AVCODEC_JPEGXL_H */
diff --git a/libavcodec/jpegxl_parser.c b/libavcodec/jpegxl_parser.c
new file mode 100644
index 0000000000..e98dbd4b02
--- /dev/null
+++ b/libavcodec/jpegxl_parser.c
@@ -0,0 +1,941 @@
+/*
+ * JPEG XL parser
+ * Copyright (c) 2021 Leo Izen <leo.izen@gmail.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * JPEG XL parser
+ */
+
+#include <inttypes.h>
+#include <stdlib.h>
+
+#include "libavutil/error.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/macros.h"
+#include "libavutil/mem.h"
+
+#define BITSTREAM_READER_LE
+
+#include "codec_id.h"
+#include "config.h"
+#include "get_bits.h"
+#include "jpegxl.h"
+#include "parser.h"
+
+enum JpegXLExtraChannelType {
+    FF_JPEGXL_CT_ALPHA = 0,
+    FF_JPEGXL_CT_DEPTH,
+    FF_JPEGXL_CT_SPOT_COLOR,
+    FF_JPEGXL_CT_SELECTION_MASK,
+    FF_JPEGXL_CT_BLACK,
+    FF_JPEGXL_CT_CFA,
+    FF_JPEGXL_CT_THERMAL,
+    FF_JPEGXL_CT_NON_OPTIONAL = 15,
+    FF_JPEGXL_CT_OPTIONAL
+};
+
+enum JpegXLColorSpace {
+    FF_JPEGXL_CS_RGB = 0,
+    FF_JPEGXL_CS_GRAY,
+    FF_JPEGXL_CS_XYB,
+    FF_JPEGXL_CS_UNKNOWN
+};
+
+enum JpegXLWhitePoint {
+    FF_JPEGXL_WP_D65 = 1,
+    FF_JPEGXL_WP_CUSTOM,
+    FF_JPEGXL_WP_E = 10,
+    FF_JPEGXL_WP_DCI = 11
+};
+
+enum JpegXLPrimaries {
+    FF_JPEGXL_PR_SRGB = 1,
+    FF_JPEGXL_PR_CUSTOM,
+    FF_JPEGXL_PR_2100 = 9,
+    FF_JPEGXL_PR_P3 = 11,
+};
+
+enum JpegXLTransferFunction {
+    FF_JPEGXL_TF_709 = 1,
+    FF_JPEGXL_TF_UNKNOWN,
+    FF_JPEGXL_TF_LINEAR = 8,
+    FF_JPEGXL_TF_SRGB = 13,
+    FF_JPEGXL_TF_PQ = 16,
+    FF_JPEGXL_TF_DCI,
+    FF_JPEGXL_TF_HLG
+};
+
+enum JpegXLRenderingIntent {
+    FF_JPEGXL_RI_PERCEPTUAL = 0,
+    FF_JPEGXL_RI_RELATIVE,
+    FF_JPEGXL_RI_SATURATION,
+    FF_JPEGXL_RI_ABSOLUTE
+};
+
+typedef struct JpegXLExtraChannelInfo {
+    enum JpegXLExtraChannelType type;
+    uint32_t bits_per_sample;
+    uint32_t exp_bits_per_sample;
+    uint32_t dim_shift;
+    size_t name_len;
+    int alpha_associated;
+    float red;
+    float green;
+    float blue;
+    float solidity;
+    uint32_t cfa_channel;
+} JpegXLExtraChannelInfo;
+
+typedef struct JpegXLHeader {
+    uint32_t width;
+    uint32_t height;
+    int orientation;
+    /* zero if not present */
+    uint32_t intrinsic_width;
+    uint32_t intrinsic_height;
+    uint32_t preview_width;
+    uint32_t preview_height;
+    /* BEGIN animation header */
+    uint32_t anim_tb_num;
+    uint32_t anim_tb_denom;
+    uint32_t anim_loop_count;
+    int anim_have_pts;
+    /* END animation header */
+
+    uint32_t bits_per_sample;
+    uint32_t exp_bits_per_sample;
+
+    int modular_16bit_buffers;
+
+    uint32_t num_extra_channels;
+
+    /*
+     * an array of extra channel info
+     * with length num_extra_channels
+     * this is not NULL-terminated
+     */
+    JpegXLExtraChannelInfo extra_channel_info[256];
+
+    int xyb_encoded;
+
+    /* BEGIN color encoding bundle */
+    int have_icc_profile;
+    enum JpegXLColorSpace color_space;
+    enum JpegXLWhitePoint white_point;
+    uint32_t white_ux;
+    uint32_t white_uy;
+    enum JpegXLPrimaries primaries;
+    uint32_t red_ux;
+    uint32_t red_uy;
+    uint32_t green_ux;
+    uint32_t green_uy;
+    uint32_t blue_ux;
+    uint32_t blue_uy;
+    /*
+     * if this is less than 1 << 24,
+     * then interpret it as a gamma value
+     * If this is greater than or equal to 1 << 24,
+     * then subtract 1 << 24 and interpret it as a
+     * an enum JpegXLTransferFunction
+     */
+    int have_gamma;
+    uint32_t transfer_function;
+    enum JpegXLRenderingIntent rendering_intent;
+    /* END color encoding bundle */
+
+    /* BEGIN tone mapping bundle */
+    float intensity_target;
+    float min_nits;
+    int relative_to_max_display;
+    float linear_below;
+    /* END tone mapping bundle */
+
+    /* each extension bit determines which extension matters */
+    uint64_t extensions;
+    uint64_t extension_bits[64];
+
+    int default_transform;
+
+    int have_opsin_inv;
+    float opsin_inverse_matrix[16];
+
+    uint32_t cw_mask;
+    float up2_weight[15];
+    float up4_weight[55];
+    float up8_weight[210];
+
+    /*
+     * this is not provided by the header,
+     * but rather, by the container
+     * raw Jpeg XL Codestreams are level 5
+     * the container can choose to up it to 10
+     */
+    int level;
+
+} JpegXLHeader;
+
+typedef struct JpegXLParseContext {
+    ParseContext pc;
+    GetBitContext gb;
+    int box_size;
+    uint32_t box_tag;
+    int box_index;
+    int level;
+    int container;
+    int found_codestream;
+} JpegXLParseContext;
+
+#define jxl_bits(n) jpegxl_get_bits(NULL, jxlr, (n))
+#define jxl_u32(c0, c1, c2, c3, u0, u1, u2, u3) jpegxl_u32(jxlr, \
+    (uint32_t[]){c0, c1, c2, c3}, (uint32_t[]){u0, u1, u2, u3})
+#define jxl_enum() jxl_u32(0, 1, 2, 18, 0, 0, 4, 6)
+
+#define jxl_parse_errv(type, ...) av_log(avctx, AV_LOG_DEBUG, \
+    "At position: %d, invalid " type "\n", jxlr->gb.index, __VA_ARGS__)
+
+#define jxl_parse_err(msg) jxl_parse_errv("%s", (msg))
+
+static int jpegxl_skip_boxes(void *avctx, JpegXLParseContext *jxlr)
+{
+    uint64_t size = 0;
+    uint32_t tag = 0;
+    char tag_str[5];
+    int remaining;
+    while (1) {
+        if (jxlr->box_index < 0) {
+            if (jxlr->box_size > 1) {
+                size = jxlr->box_size / 8 + 8;
+                tag = jxlr->box_tag;
+            } else if (jxlr->box_size == 1) {
+                size = 1;
+                tag = jxlr->box_tag;
+            } else {
+                size = 0;
+            }
+            jxlr->box_index = 0;
+        } else {
+            size = 0;
+        }
+
+        remaining = jxlr->gb.size_in_bits - jxlr->gb.index;
+        remaining -= remaining % 8;
+        if (remaining < 64)
+            goto box_eof;
+
+        if (size == 0) {
+            tag = 0;
+            for (int k = 0; k < 4; k++)
+                size = (size << 8) | get_bits(&jxlr->gb, 8);
+            remaining -= 32;
+        }
+        if (tag == 0) {
+            for (int k = 0; k < 4; k++)
+                tag = (tag << 8) | get_bits(&jxlr->gb, 8);
+            remaining -= 32;
+        }
+
+        /* extra 64-bit size field */
+        if (size == 1) {
+            if (remaining < 64)
+                goto box_eof;
+            size = 0;
+            for (int k = 0; k < 8; k++)
+                size = (size << 8) | get_bits(&jxlr->gb, 8);
+            size -= 8;
+            remaining -= 64;
+        }
+
+        if (size > 0 && size < 9)
+            return 1; /* invalid ISOBMFF box size */
+
+        /* box too big for GetBitContext */
+        /* size - 40 => (size - 8) - 32 */
+        if (size > 40 && size - 40 > INT_MAX / 8)
+            return 1;
+
+        /* turn size into something the parser can use */
+        if (size > 0)
+            size = (size - 8) * 8;
+
+        /* partial jxl codestream box */
+        if (tag == MKBETAG('j','x','l','p')) {
+            if (remaining < 32)
+                goto box_eof;
+            /* 32-bit box index, we ignore it */
+            skip_bits_long(&jxlr->gb, 32);
+            remaining -= 32;
+            break;
+        }
+        /* full jxl codestream box */
+        if (tag == MKBETAG('j','x','l','c'))
+            break;
+        /* jxl level box */
+        if (tag == MKBETAG('j','x','l','l')) {
+            if (size != 8)
+                return 1; /* illegal jxll box */
+            if (remaining < 8)
+                goto box_eof;
+            jxlr->level = get_bits(&jxlr->gb, 8);
+            remaining -= 8;
+            continue;
+        }
+        /* any other box is skipped at this point */
+        AV_WB32(tag_str, tag);
+        av_log(avctx, AV_LOG_VERBOSE, "skipping jxl container box: %s\n", tag_str);
+       
+        /* zero size means -> eof, nothing more to skip */
+        if (size == 0)
+            break;
+
+        if (size - 1 > remaining) {
+            skip_bits_long(&jxlr->gb, remaining);
+            size -= remaining;
+            goto box_eof;
+        }
+
+        skip_bits_long(&jxlr->gb, size);
+    }
+
+    jxlr->box_size = size;
+    jxlr->box_tag = tag;
+    return 0;
+
+box_eof:
+    jxlr->box_size = size;
+    jxlr->box_tag = tag;
+    return 2;
+}
+
+/*
+ * get from 1-64 bits from a JpegXLParseContext
+ */
+static uint64_t jpegxl_get_bits(void *avctx, JpegXLParseContext *jxlr, int bits)
+{
+    if (jxlr->box_size) {
+        if (bits > jxlr->box_size) {
+            int remaining = jxlr->box_size;
+            uint64_t ret = jpegxl_get_bits(avctx, jxlr, remaining);
+            /* go to the next box */
+            int status = jpegxl_skip_boxes(avctx, jxlr);
+            if (status)
+                return 0;
+            ret |= jpegxl_get_bits(avctx, jxlr, bits - remaining) << remaining;
+            return ret;
+        }
+        jxlr->box_size -= bits;
+    }
+    return get_bits64(&jxlr->gb, bits);
+}
+
+static uint32_t jpegxl_u32(JpegXLParseContext *jxlr,
+        const uint32_t constants[4], const uint32_t ubits[4])
+{
+    uint32_t ret, choice = jxl_bits(2);
+    ret = constants[choice];
+    if (ubits[choice])
+        ret += jxl_bits(ubits[choice]);
+    return ret;
+}
+
+static uint64_t jpegxl_u64(JpegXLParseContext *jxlr)
+{
+    uint64_t shift = 12, ret;
+    switch (jxl_bits(2)) {
+    case 0:
+        ret = 0;
+        break;
+    case 1:
+        ret = 1 + jxl_bits(4);
+        break;
+    case 2:
+        ret = 17 + jxl_bits(8);
+        break;
+    case 3:
+        ret = jxl_bits(12);
+        while (jxl_bits(1)) {
+            if (shift < 60) {
+                ret |= jxl_bits(8) << shift;
+                shift += 8;
+            } else {
+                ret |= jxl_bits(4) << shift;
+                break;
+            }
+        }
+        break;
+    }
+    return ret;
+}
+
+static float jpegxl_f16(JpegXLParseContext *jxlr)
+{
+    uint32_t mantissa = jxl_bits(10) << 13;
+    uint32_t biased_exponent = jxl_bits(5);
+    if (biased_exponent == 31)
+        mantissa |= 0xFF << 23;
+    else
+        mantissa |= ((biased_exponent - 15 + 127) & 0xFF) << 23;
+    return av_int2float(mantissa);
+}
+
+static uint32_t jpegxl_width_from_ratio(uint32_t height, int ratio)
+{
+    uint64_t height64 = height;
+    switch (ratio) {
+    case 1:
+        return height;
+    case 2:
+        return (uint32_t)((height64 * 12) / 10);
+    case 3:
+        return (uint32_t)((height64 * 4) / 3);
+    case 4:
+        return (uint32_t)((height64 * 3) / 2);
+    case 5:
+        return (uint32_t)((height64 * 16) / 9);
+    case 6:
+        return (uint32_t)((height64 * 5) / 4);
+    case 7:
+        return (uint32_t)(height64 * 2);
+    default:
+        return 0; /* manual width */
+    }
+}
+
+
+static int jpegxl_parse_size_header(JpegXLParseContext *jxlr,
+        uint32_t *width, uint32_t *height)
+{
+    uint32_t w, h;
+    if (jxl_bits(1)) {
+        /* small size header */
+        h = (jxl_bits(5) + 1) << 3;
+        w = jpegxl_width_from_ratio(h, jxl_bits(3));
+        if (!w)
+            w = (jxl_bits(5) + 1) << 3;
+    } else {
+        /* large size header */
+        h = 1 + jxl_u32(0, 0, 0, 0, 9, 13, 18, 30);
+        w = jpegxl_width_from_ratio(h, jxl_bits(3));
+        if (!w)
+            w = 1 + jxl_u32(0, 0, 0, 0, 9, 13, 18, 30);
+    }
+    *width = w, *height = h;
+    return 0;
+}
+
+static int jpegxl_parse_preview_header(JpegXLParseContext *jxlr,
+        uint32_t *width, uint32_t *height)
+{
+    uint32_t w, h;
+    if (jxl_bits(1)) {
+        /* coded height and width divided by eight */
+        h = jxl_u32(16, 32, 1, 33, 0, 0, 5, 9) << 3;
+        w = jpegxl_width_from_ratio(h, jxl_bits(3));
+        if (!w)
+            w = jxl_u32(16, 32, 1, 33, 0, 0, 5, 9) << 3;
+    } else {
+        /* full height and width coded */
+        h = jxl_u32(1, 65, 321, 1345, 6, 8, 10, 12);
+        w = jpegxl_width_from_ratio(h, jxl_bits(3));
+        if (!w)
+            w = jxl_u32(1, 65, 321, 1345, 6, 8, 10, 12);
+    }
+    *width = w, *height = h;
+    return 0;
+}
+
+static int jpegxl_parse_animation_header(JpegXLParseContext *jxlr,
+    uint32_t *num, uint32_t *denom, uint32_t *count, int *have_pts)
+{
+    *num = jxl_u32(100, 1000, 1, 1, 0, 0, 10, 30);
+    *denom = jxl_u32(1, 1001, 1, 1, 0, 0, 8, 10);
+    *count = jxl_u32(0, 0, 0, 0, 0, 3, 16, 32);
+    *have_pts = jxl_bits(1);
+    return 0;
+}
+
+static int jpegxl_parse_bit_depth(JpegXLParseContext *jxlr,
+        uint32_t *depth, uint32_t *exp_depth)
+{
+    if (jxl_bits(1)) {
+        /* float samples */
+        *depth = jxl_u32(32, 16, 24, 1, 0, 0, 0, 6);
+        *exp_depth = jxl_bits(4) + 1;
+    } else {
+        /* integer samples */
+        *depth = jxl_u32(8, 10, 12, 1, 0, 0, 0, 6);
+        *exp_depth = 0;
+    }
+    return 0;
+}
+
+static int jpegxl_parse_extra_channel_info(JpegXLParseContext *jxlr,
+        JpegXLExtraChannelInfo *info, int level)
+{
+    int status = 0;
+    int all_default = jxl_bits(1);
+
+    if (!all_default) {
+        info->type = jxl_enum();
+        if (info->type > 63)
+            return 1; /* enum types cannot be 64+ */
+        status = jpegxl_parse_bit_depth(jxlr, &info->bits_per_sample, &info->exp_bits_per_sample);
+        if (status)
+            return status;
+        info->dim_shift = jxl_u32(0, 3, 4, 1, 0, 0, 0, 3);
+        /* max of name_len is 1071 = 48 + 2^10 - 1 */
+        info->name_len = jxl_u32(0, 0, 16, 48, 0, 4, 5, 10);
+    } else {
+        info->type = FF_JPEGXL_CT_ALPHA;
+        info->bits_per_sample = 8;
+        info->exp_bits_per_sample = 0;
+    }
+
+    /* skip over the name as it is not used */
+    jxl_bits(8 * info->name_len);
+
+    info->alpha_associated = !all_default && info->type == FF_JPEGXL_CT_ALPHA && jxl_bits(1);
+
+    if (info->type == FF_JPEGXL_CT_SPOT_COLOR) {
+        info->red = jpegxl_f16(jxlr);
+        info->green = jpegxl_f16(jxlr);
+        info->blue = jpegxl_f16(jxlr);
+        info->solidity = jpegxl_f16(jxlr);
+    }
+
+    if (info->type == FF_JPEGXL_CT_CFA)
+        info->cfa_channel = jxl_u32(1, 0, 3, 19, 0, 2, 4, 8);
+    else
+        info->cfa_channel = 1;
+
+    if (info->type == FF_JPEGXL_CT_BLACK && level < 10)
+        return 1;
+
+    return 0;
+}
+
+/**
+ * Parse a JpegXL Codestream Header and read it into the argument Header
+ * @return 0 upon success, 1 upon error
+ */
+static int jpegxl_parse_codestream_header(void *avctx,
+                                          JpegXLParseContext *jxlr,
+                                          JpegXLHeader *header)
+{
+    int all_default, extra_fields = 0, status;
+
+    /* signature check */
+    if (jxl_bits(16) != FF_JPEGXL_CODESTREAM_SIGNATURE_LE) {
+        av_log(avctx, AV_LOG_ERROR, "Failed JPEG XL Signature Check\n");
+        goto fail;
+    }
+
+    status = jpegxl_parse_size_header(jxlr, &header->width, &header->height);
+    if (status) {
+        jxl_parse_err("size header");
+        goto fail;
+    }
+
+    if (jxlr->level < 10) {
+        /* level 5 codestream */
+        if (header->width > (1 << 18) || header->height > (1 << 18)
+            || (header->width >> 4) * (header->height >> 4) > (1 << 20)) {
+                jxl_parse_err("width or height or both");
+                goto fail;
+            }
+        header->level = 5;
+    } else {
+        /* level 10 codestream */
+        if (header->width > (1 << 30) || header->height > (1 << 30)
+            || (header->width >> 14) * (header->height >> 14) > (1 << 12)) {
+                jxl_parse_err("width or height or both");
+                goto fail;
+            }
+        header->level = 10;
+    }
+
+    all_default = jxl_bits(1);
+
+    if (!all_default)
+        extra_fields = jxl_bits(1);
+
+    if (extra_fields) {
+        header->orientation = jxl_bits(3);
+        if (header->orientation > 3)
+            FFSWAP(uint32_t, header->width, header->height);
+
+        /* intrinstic size */
+        if (jxl_bits(1)) {
+            status = jpegxl_parse_size_header(jxlr, &header->intrinsic_width, &header->intrinsic_height);
+            if (status) {
+                jxl_parse_err("intrinstic size header");
+                goto fail;
+            }
+        }
+
+        /* preview header */
+        if (jxl_bits(1)) {
+            status = jpegxl_parse_preview_header(jxlr,
+                &header->preview_width, &header->preview_height);
+            if (status) {
+                jxl_parse_err("preview header");
+                goto fail;
+            }
+            if (header->preview_width > 4096 || header->preview_height > 4096) {
+                jxl_parse_errv("preview header size %" PRIu32 ", %" PRIu32,
+                    header->preview_width, header->preview_height);
+                goto fail;
+            }
+        }
+
+        /* animation header */
+        if (jxl_bits(1)) {
+            status = jpegxl_parse_animation_header(jxlr,
+                &header->anim_tb_num, &header->anim_tb_denom,
+                &header->anim_loop_count, &header->anim_have_pts);
+            if (status) {
+                jxl_parse_err("animation header");
+                goto fail;
+            }
+        }
+
+    }
+
+    if (!all_default) {
+        status = jpegxl_parse_bit_depth(jxlr,
+            &header->bits_per_sample, &header->exp_bits_per_sample);
+        if (status) {
+            jxl_parse_err("bit depth header");
+            goto fail;
+        }
+
+        header->modular_16bit_buffers = jxl_bits(1);
+
+        if (!header->modular_16bit_buffers && header->level < 10) {
+            jxl_parse_err("modular 16bit buffers");
+            goto fail;
+        }
+
+        header->num_extra_channels = jxl_u32(0, 1, 2, 1, 0, 0, 4, 12);
+        if (header->num_extra_channels > 256 ||
+            header->level < 10 && header->num_extra_channels > 4) {
+                jxl_parse_err("too many extra channels");
+                goto fail;
+        }
+        for (uint32_t i = 0; i < header->num_extra_channels; i++) {
+            status = jpegxl_parse_extra_channel_info(jxlr, &header->extra_channel_info[i], header->level);
+            if (status) {
+                jxl_parse_errv("extra channel number %" PRIu32, i);
+                goto fail;
+            }
+        }
+
+        header->xyb_encoded = jxl_bits(1);
+
+        if (jxl_bits(1)) {
+            /* all_default for color encoding */
+            header->have_icc_profile = 0;
+            header->color_space = FF_JPEGXL_CS_RGB;
+            header->white_point = FF_JPEGXL_WP_D65;
+            header->primaries = FF_JPEGXL_PR_SRGB;
+            header->transfer_function = (1 << 24) + FF_JPEGXL_TF_SRGB;
+            header->rendering_intent = FF_JPEGXL_RI_RELATIVE;
+        } else {
+            header->have_icc_profile = jxl_bits(1);
+            header->color_space = jxl_enum();
+            if (header->color_space > 63) {
+                jxl_parse_errv("color space enum %" PRIu32, header->white_point);
+                goto fail;
+            }
+            if (header->color_space != FF_JPEGXL_CS_XYB
+                    && !header->have_icc_profile) {
+                header->white_point = jxl_enum();
+                if (header->white_point > 63) {
+                    jxl_parse_errv("white point enum %" PRIu32, header->white_point);
+                    goto fail;
+                }
+            } else {
+                header->white_point = FF_JPEGXL_WP_D65;
+            }
+            if (header->white_point == FF_JPEGXL_WP_CUSTOM) {
+                header->white_ux = jxl_u32(0, 524288, 1048576, 2097152, 19, 19, 20, 21);
+                header->white_uy = jxl_u32(0, 524288, 1048576, 2097152, 19, 19, 20, 21);
+            }
+            if (header->color_space != FF_JPEGXL_CS_XYB
+                    && header->color_space != FF_JPEGXL_CS_GRAY
+                    && !header->have_icc_profile) {
+                header->primaries = jxl_enum();
+                if (header->primaries > 63) {
+                    jxl_parse_errv("primaries enum %" PRIu32, header->primaries);
+                    goto fail;
+                }
+            } else {
+                header->primaries = FF_JPEGXL_PR_SRGB;
+            }
+            if (header->primaries == FF_JPEGXL_PR_CUSTOM) {
+                header->red_ux = jxl_u32(0, 524288, 1048576, 2097152, 19, 19, 20, 21);
+                header->red_uy = jxl_u32(0, 524288, 1048576, 2097152, 19, 19, 20, 21);
+                header->green_ux = jxl_u32(0, 524288, 1048576, 2097152, 19, 19, 20, 21);
+                header->green_uy = jxl_u32(0, 524288, 1048576, 2097152, 19, 19, 20, 21);
+                header->blue_ux = jxl_u32(0, 524288, 1048576, 2097152, 19, 19, 20, 21);
+                header->blue_uy = jxl_u32(0, 524288, 1048576, 2097152, 19, 19, 20, 21);
+            }
+            if (!header->have_icc_profile) {
+                if (jxl_bits(1)) {
+                    /* this is gamma */
+                    header->transfer_function = jxl_bits(24);
+                } else {
+                    header->transfer_function = jxl_enum();
+                    if (header->transfer_function > 63) {
+                        jxl_parse_errv("transfer function enum %" PRIu32, header->transfer_function);
+                        goto fail;
+                    }
+                    /*
+                     * higher than the highest possible gamma value
+                     * marks it as an enum isntead of gamma
+                     */
+                    header->transfer_function += 1 << 24;
+                }
+                header->rendering_intent = jxl_enum();
+                if (header->rendering_intent > 63) {
+                    jxl_parse_errv("rendering intent enum %" PRIu32, header->rendering_intent);
+                    goto fail;
+                }
+            } else {
+                header->transfer_function = (1 << 24) + FF_JPEGXL_TF_SRGB;
+                header->rendering_intent = FF_JPEGXL_RI_RELATIVE;
+            }
+        }
+
+        /* intensity_target should be set to 255 without it,
+         * but it's unused
+         * lazy && works with this macro */
+        if (extra_fields && !jxl_bits(1)) {
+            /*
+             * these are 16-bit floats
+             * since these fields are not used at the moment,
+             * we skip 16 bits for each instead of calling
+             * jpegxl_f16(jxlr) and assigning
+             */
+            /* intensity target */
+            jxl_bits(16);
+            /* min nits */
+            jxl_bits(16);
+            /* relative to max display */
+            jxl_bits(1);
+            /* linear below */
+            jxl_bits(16);
+        }
+
+        header->extensions = jpegxl_u64(jxlr);
+        if (header->extensions) {
+            for (int i = 0; i < 64; i++) {
+                if (header->extensions & (UINT64_C(1) << i))
+                    header->extension_bits[i] = jpegxl_u64(jxlr);
+            }
+        }
+
+    } else {
+        header->modular_16bit_buffers = 1;
+        header->xyb_encoded = 1;
+    }
+
+    header->default_transform = jxl_bits(1);
+
+    /* opsin_inverse_matrix skipped over because it is not used atm */
+    if (!header->default_transform && header->xyb_encoded && !jxl_bits(1)) {
+        header->have_opsin_inv = 1;
+        jxl_bits(16 * 16);
+    }
+
+    if (!header->default_transform)
+        header->cw_mask = jxl_bits(3);
+
+    /*
+     * up2_weight skipped over because it is not used atm
+     */
+    if (header->cw_mask & 1)
+        jxl_bits(16 * 15);
+
+    /*
+     * up4_weight skipped over because it is not used atm
+     */
+    if (header->cw_mask & 2)
+        jxl_bits(16 * 55);
+
+    /*
+     * up8_weight skipped over because it is not used atm
+     */
+    if (header->cw_mask & 4)
+        jxl_bits(16 * 210);
+
+    /* zero pad to byte */
+    if (!header->have_icc_profile) {
+        int byte_remaining = 7 - (jxlr->gb.index - 1) % 8;
+        if (byte_remaining && jxl_bits(byte_remaining)) {
+            jxl_parse_err("zero padding to byte");
+            goto fail;
+        }
+    }
+
+    /* bits consumed > buflen */
+    if (jxlr->gb.index > jxlr->gb.size_in_bits) {
+        jxl_parse_err("unexpected end of file");
+        goto fail;
+    }
+
+    return 0;
+
+fail:
+    return 1;
+}
+
+static int jpegxl_parse_header(void *avctx, JpegXLParseContext *jxlr, JpegXLHeader *header)
+{
+    int status;
+    if (jxlr->container) {
+        status = jpegxl_skip_boxes(avctx, jxlr);
+        if (status)
+            return status;
+    }
+    return jpegxl_parse_codestream_header(avctx, jxlr, header);
+}
+
+int avpriv_jpegxl_verify_codestream_header(void *avctx, uint8_t *buf, int buflen)
+{
+    JpegXLParseContext jxlri = { 0 };
+    JpegXLHeader header = { 0 };
+    int status;
+    init_get_bits8(&jxlri.gb, buf, buflen);
+    jxlri.level = 5;
+    status = jpegxl_parse_codestream_header(avctx, &jxlri, &header);
+    return status;
+}
+
+static enum AVPixelFormat jpegxl_header_get_pixfmt(JpegXLHeader *header)
+{
+    int alpha = 0;
+    for (int i = 0; i < header->num_extra_channels; i++) {
+        if (header->extra_channel_info[i].type == FF_JPEGXL_CT_ALPHA) {
+            alpha = 1;
+            break;
+        }
+    }
+    if (header->color_space == FF_JPEGXL_CS_GRAY) {
+        if (header->bits_per_sample <= 8)
+            return alpha ? AV_PIX_FMT_YA8 : AV_PIX_FMT_GRAY8;
+        if (header->bits_per_sample > 16 || header->exp_bits_per_sample)
+            return alpha ? AV_PIX_FMT_NONE : AV_PIX_FMT_GRAYF32LE;
+        return alpha ? AV_PIX_FMT_YA16LE : AV_PIX_FMT_GRAY16LE;
+    } else if (header->color_space == FF_JPEGXL_CS_RGB
+            || header->color_space == FF_JPEGXL_CS_XYB) {
+        if (header->bits_per_sample <= 8)
+            return alpha ? AV_PIX_FMT_RGBA : AV_PIX_FMT_RGB24;
+        if (header->bits_per_sample > 16 || header->exp_bits_per_sample)
+            return alpha ? AV_PIX_FMT_GBRAPF32LE : AV_PIX_FMT_GBRPF32LE;
+        return alpha ? AV_PIX_FMT_RGBA64LE : AV_PIX_FMT_RGB48LE;
+    }
+    return AV_PIX_FMT_NONE;
+}
+
+static av_cold int jpegxl_parse_init(AVCodecParserContext *s1)
+{
+    s1->pict_type = AV_PICTURE_TYPE_NONE;
+    return 0;
+}
+
+static int jpegxl_parse(AVCodecParserContext *s1,
+                     AVCodecContext *avctx,
+                     const uint8_t **poutbuf, int *poutbuf_size,
+                     const uint8_t *buf, int buf_size)
+{
+    JpegXLParseContext *jxlr = s1->priv_data;
+    JpegXLHeader header = { 0 };
+    int next = END_NOT_FOUND, status = 0;
+    int i = 0;
+
+    *poutbuf_size = 0;
+    *poutbuf = NULL;
+
+    if (buf_size == 0 || s1->flags & PARSER_FLAG_COMPLETE_FRAMES) {
+        /* eof is a frame boundary */
+        next = buf_size;
+    } else if (!jxlr->pc.frame_start_found) {
+        /* look for stream signature */
+        uint64_t state64 = jxlr->pc.state64;
+        for (; i < buf_size; i++) {
+            state64 = (state64 << 8) | buf[i];
+            if ((state64 & 0xFFFF) == FF_JPEGXL_CODESTREAM_SIGNATURE_BE) {
+                i -= 1;
+                jxlr->pc.frame_start_found = 1;
+                jxlr->container = 0;
+                jxlr->level = 5;
+                break;
+            }
+            if (state64 == FF_JPEGXL_CONTAINER_SIGNATURE_BE) {
+                i -= 7;
+                jxlr->pc.frame_start_found = 1;
+                jxlr->container = 1;
+                jxlr->level = 5;
+                break;
+            }
+        }
+        jxlr->pc.state64 = state64;
+    }
+
+    if (jxlr->pc.frame_start_found && !jxlr->found_codestream) {
+        init_get_bits8(&jxlr->gb, buf + i, buf_size - i);
+        status = jpegxl_parse_header(NULL, jxlr, &header);
+        if (status == 0) {
+            /* parsed successfully */
+            s1->pict_type = AV_PICTURE_TYPE_I;
+            s1->key_frame = 1;
+            s1->width = avctx->width = header.width;
+            s1->height = avctx->height = header.height;
+            s1->format = avctx->pix_fmt = jpegxl_header_get_pixfmt(&header);
+        }
+        if (status == 2)
+            /* need higher probesize */
+            jxlr->found_codestream = 0;
+        else
+            jxlr->found_codestream = 1;
+    }
+
+    if (ff_combine_frame(&jxlr->pc, next, &buf, &buf_size) < 0) {
+        *poutbuf = NULL;
+        *poutbuf_size = 0;
+        return buf_size;
+    }
+
+    jxlr->pc.frame_start_found = 0;
+
+    *poutbuf = buf + i;
+    *poutbuf_size = buf_size - i;
+
+    return next;
+}
+
+const AVCodecParser ff_jpegxl_parser = {
+    .codec_ids      = { AV_CODEC_ID_JPEGXL },
+    .priv_data_size = sizeof(JpegXLParseContext),
+    .parser_init    = jpegxl_parse_init,
+    .parser_parse   = jpegxl_parse,
+    .parser_close   = ff_parse_close,
+};
diff --git a/libavcodec/parsers.c b/libavcodec/parsers.c
index 6b40c18d80..18a40eceea 100644
--- a/libavcodec/parsers.c
+++ b/libavcodec/parsers.c
@@ -52,6 +52,7 @@ extern const AVCodecParser ff_h264_parser;
 extern const AVCodecParser ff_hevc_parser;
 extern const AVCodecParser ff_ipu_parser;
 extern const AVCodecParser ff_jpeg2000_parser;
+extern const AVCodecParser ff_jpegxl_parser;
 extern const AVCodecParser ff_mjpeg_parser;
 extern const AVCodecParser ff_mlp_parser;
 extern const AVCodecParser ff_mpeg4video_parser;
diff --git a/libavcodec/version.h b/libavcodec/version.h
index a744e7469f..26ee41eb1f 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -29,7 +29,7 @@
 
 #include "version_major.h"
 
-#define LIBAVCODEC_VERSION_MINOR  25
+#define LIBAVCODEC_VERSION_MINOR  26
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
