diff --git a/MAINTAINERS b/MAINTAINERS
index c065e94498..17c0104672 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -187,6 +187,7 @@ 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
@@ -615,6 +616,7 @@ 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 9577062eec..4a41bb2825 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -43,6 +43,7 @@ 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 0974ee03de..0f3d0f910b 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -1862,6 +1862,15 @@ 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 ab265ec584..551a516446 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..434247a85d
--- /dev/null
+++ b/libavcodec/jpegxl.h
@@ -0,0 +1,204 @@
+/*
+ * 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>
+
+#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
+
+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;
+    /* utf-8 */
+    char *name;
+    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;
+
+    /*
+     * NULL if no extra channels
+     * otherwise an array of extra channel info
+     * with length num_extra_channels
+     */
+    JpegXLExtraChannelInfo *extra_channel_info;
+
+    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 1 << 24, then
+     * subtract 1 << 24 and interpret it as a
+     * an enum JpegXLTransferFunction
+     */
+    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 */
+
+    uint64_t extensions;
+    /* if extensions is nonzero, this will be length 64 */
+    uint64_t *extension_bits;
+
+    int default_transform;
+
+    /* if present, an array of length 16 */
+    /* NULL if not present */
+    float *opsin_inverse_matrix;
+
+    uint32_t cw_mask;
+
+    /* if these are not present
+     * use NULL for these pointers
+     * otherwise up2_weight is an
+     * array of length 15, up4_weight
+     * is length 55, and up8_weight is
+     * length 210
+     */
+    float *up2_weight;
+    float *up4_weight;
+    float *up8_weight;
+
+    /*
+     * 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;
+
+/**
+ * @return 0 upon valid, nonzero upon some parse error
+ */
+int avpriv_jpegxl_verify_codestream_header(void *avctx, uint8_t *buf, size_t buflen, int level);
+
+#endif /* AVCODEC_JPEGXL_H */
diff --git a/libavcodec/jpegxl_parser.c b/libavcodec/jpegxl_parser.c
new file mode 100644
index 0000000000..3efbc71a53
--- /dev/null
+++ b/libavcodec/jpegxl_parser.c
@@ -0,0 +1,794 @@
+/*
+ * 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 <stdint.h>
+#include <inttypes.h>
+#include <stdlib.h>
+
+#ifndef BITSTREAM_READER_LE
+#define BITSTREAM_READER_LE
+#endif
+#ifdef CACHED_BITSTREAM_READER
+#undef CACHED_BITSTREAM_READER
+#endif
+#define CACHED_BITSTREAM_READER 1
+
+#include "libavutil/error.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/mem.h"
+
+#include "get_bits.h"
+#include "codec_id.h"
+#include "parser.h"
+#include "jpegxl.h"
+#include "config.h"
+
+#if CONFIG_JPEGXL_PARSER
+
+typedef struct JpegXLParseContext {
+    ParseContext pc;
+    GetBitContext gb;
+    size_t buflen;
+    size_t bits_read;
+} JpegXLParseContext;
+
+#define jxl_bits(n) jpegxl_get_bits(jxlr, (n))
+#define jxl_enum() jpegxl_u32(jxlr, (uint32_t[]){0, 1, 2, 18}, (uint32_t[]){0, 0, 4, 6})
+
+#define jxl_parse_errv(type, value) av_log(avctx, AV_LOG_DEBUG, \
+    "Invalid " type " at position: %zu", \
+    value, jxlr->bits_read)
+
+#define jxl_parse_errvv(type, v1, v2) av_log(avctx, AV_LOG_DEBUG, \
+    "Invalid " type " at position: %zu", \
+    v1, v2, jxlr->bits_read)
+
+#define jxl_parse_err(type) jxl_parse_errv("%s", type)
+
+static void jpegxl_init_pc(JpegXLParseContext *jxlr, const uint8_t *buf, size_t buflen)
+{
+    memset(&jxlr->pc, 0, sizeof(ParseContext));
+    jxlr->buflen = buflen;
+    jxlr->bits_read = 0;
+    init_get_bits8(&jxlr->gb, buf, buflen);
+}
+
+static uint64_t jpegxl_get_bits(JpegXLParseContext *jxlr, size_t bits)
+{
+    if (!bits)
+        return 0;
+    if (bits > INT_MAX)
+        /* what are you doing with all those bits... */
+        return 0;
+    jxlr->bits_read += bits;
+    /* extra buffer size of 8 bytes */
+    if ((jxlr->bits_read + 1) / 8 + 8 > jxlr->buflen - 1)
+        /* overflowing buffer */
+        return 0;
+    while (bits > 64) {
+        size_t bitcount = (bits - 1) % 64 + 1;
+        get_bits_long(&jxlr->gb, bitcount);
+        bits -= bitcount;
+    }
+    return get_bits_long(&jxlr->gb, bits);
+}
+
+static uint32_t jpegxl_u32(JpegXLParseContext *jxlr,
+        uint32_t *constants, uint32_t *ubits)
+{
+    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)
+{
+    float ret;
+    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;
+    memcpy(&ret, &mantissa, sizeof(float));
+    return ret;
+}
+
+static uint32_t jpegxl_width_from_ratio(uint32_t height, int ratio)
+{
+    switch (ratio){
+    case 1:
+        return height;
+    case 2:
+        return (height * 12) / 10;
+    case 3:
+        return (height * 4) / 3;
+    case 4:
+        return (height * 3) / 2;
+    case 5:
+        return (height * 16) / 9;
+    case 6:
+        return (height * 5) / 4;
+    case 7:
+        return height * 2;
+    default:
+        /* manual width */
+        return 0;
+    }
+}
+
+
+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 + jpegxl_u32(jxlr,
+                    (uint32_t[]){0, 0, 0, 0}, (uint32_t[]){9, 13, 18, 30});
+        w = jpegxl_width_from_ratio(h, jxl_bits(3));
+        if (!w)
+            w = 1 + jpegxl_u32(jxlr,
+                        (uint32_t[]){0, 0, 0, 0}, (uint32_t[]){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)) {
+        /* div8 */
+        h = jpegxl_u32(jxlr,
+            (uint32_t[]){16, 32, 1, 33}, (uint32_t[]){0, 0, 5, 9}) << 3;
+        w = jpegxl_width_from_ratio(h, jxl_bits(3));
+        if (!w)
+            w = jpegxl_u32(jxlr,
+                    (uint32_t[]){16, 32, 1, 33}, (uint32_t[]){0, 0, 5, 9}) << 3;
+    } else {
+        /* full */
+        h = jpegxl_u32(jxlr,
+                (uint32_t[]){1, 65, 321, 1345}, (uint32_t[]){6, 8, 10, 12});
+        w = jpegxl_width_from_ratio(h, jxl_bits(3));
+        if (!w)
+            w = jpegxl_u32(jxlr,
+                    (uint32_t[]){1, 65, 321, 1345}, (uint32_t[]){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)
+{
+    uint32_t n, d, c;
+    int p;
+    n = jpegxl_u32(jxlr,
+            (uint32_t[]){100, 1000, 1, 1}, (uint32_t[]){0, 0, 10, 30});
+    d = jpegxl_u32(jxlr,
+            (uint32_t[]){1, 1001, 1, 1}, (uint32_t[]){0, 0, 8, 10});
+    c = jpegxl_u32(jxlr,
+            (uint32_t[]){0, 0, 0, 0}, (uint32_t[]){0, 3, 16, 32});
+    p = jxl_bits(1);
+    *num = n, *denom = d, *count = c, *have_pts = p;
+    return 0;
+}
+
+static int jpegxl_parse_bit_depth(JpegXLParseContext *jxlr,
+        uint32_t *depth, uint32_t *exp_depth)
+{
+    uint32_t d, e;
+    if (jxl_bits(1)) {
+        /* float samples */
+        d = jpegxl_u32(jxlr,
+                (uint32_t[]){32, 16, 24, 1}, (uint32_t[]){0, 0, 0, 6});
+        e = jxl_bits(4) + 1;
+    } else {
+        /* integer samples */
+        d = jpegxl_u32(jxlr,
+                (uint32_t[]){8, 10, 12, 1}, (uint32_t[]){0, 0, 0, 6});
+        e = 0;
+    }
+    *depth = d, *exp_depth = e;
+    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)
+            /* enum types cannot be 64+ */
+            return 1;
+        status = jpegxl_parse_bit_depth(jxlr, &info->bits_per_sample, &info->exp_bits_per_sample);
+        if (!status)
+            return status;
+        info->dim_shift = jpegxl_u32(jxlr, (uint32_t[]){0, 3, 4, 1}, (uint32_t[]){0, 0, 0, 3});
+        info->name_len = jpegxl_u32(jxlr, (uint32_t[]){0, 0, 16, 48}, (uint32_t[]){0, 4, 5, 10});
+    } else {
+        info->type = FF_JPEGXL_CT_ALPHA;
+        info->bits_per_sample = 8;
+        info->exp_bits_per_sample = 0;
+    }
+
+    info->name = av_malloc(info->name_len + 1);
+    if (!info->name)
+        return AVERROR(ENOMEM);
+
+    for (uint32_t i = 0; i < info->name_len; i++)
+        /* there is no byte-alignment guarantee so no memcpy */
+        info->name[i] = jxl_bits(8);
+
+    /* null-terminate it for string operations */
+    /* even though we have name_len */
+    info->name[info->name_len] = '\0';
+
+    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 = jpegxl_u32(jxlr, (uint32_t[]){1, 0, 3, 19}, (uint32_t[]){0, 2, 4, 8});
+    else
+        info->cfa_channel = 1;
+
+    if (info->type == FF_JPEGXL_CT_BLACK && level < 10)
+        return 1;
+
+    return 0;
+}
+
+static void jpegxl_free_header(JpegXLHeader *header)
+{
+    if (header) {
+        if (header->extra_channel_info) {
+            for (uint32_t i = 0; i < header->num_extra_channels; i++) {
+                if (header->extra_channel_info + i)
+                    av_freep(&header->extra_channel_info[i].name);
+            }
+            av_freep(&header->extra_channel_info);
+        }
+        if (header->extension_bits)
+            av_freep(&header->extension_bits);
+        if (header->opsin_inverse_matrix)
+            av_freep(&header->opsin_inverse_matrix);
+        if (header->up2_weight)
+            av_freep(&header->up2_weight);
+        if (header->up4_weight)
+            av_freep(&header->up4_weight);
+        if (header->up8_weight)
+            av_freep(&header->up8_weight);
+        av_freep(&header);
+    }
+}
+
+/**
+ * Parse a JpegXL Codestream Header and read it into the argument Header
+ * @param level Codestream level provided by the container, 5 if raw codestream
+ * @return 0 upon success, negative upon error, and positive if the buffer overran
+ */
+static int jpegxl_parse_codestream_header(void *avctx, JpegXLParseContext *jxlr, JpegXLHeader **headerp, int level)
+{
+    JpegXLHeader *header = NULL;
+    int all_default, extra_fields = 0, status;
+
+    header = av_mallocz(sizeof(JpegXLHeader));
+    if (!header) {
+        av_log(avctx, AV_LOG_ERROR, "Could not allocate JpegXLHeader");
+        status = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    /* signature check */
+    if (jxl_bits(16) != FF_JPEGXL_CODESTREAM_SIGNATURE_LE) {
+        av_log(avctx, AV_LOG_DEBUG, "Failed JPEG XL Signature Check");
+        goto fail;
+    }
+
+    status = jpegxl_parse_size_header(jxlr,
+        &header->width, &header->height);
+    if (status) {
+        jxl_parse_err("size header");
+        goto fail;
+    }
+
+    /* level 5 codestream */
+    if (level < 10) {
+        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 {
+        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);
+        /* 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_errvv("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 && level < 10) {
+            jxl_parse_err("modular 16bit buffers");
+            goto fail;
+        }
+
+        header->num_extra_channels = jpegxl_u32(jxlr,
+                (uint32_t[]){0, 1, 2, 1}, (uint32_t[]){0, 0, 4, 12});
+        if (header->num_extra_channels > 256 ||
+            level < 10 && header->num_extra_channels > 4) {
+                jxl_parse_err("too many extra channels");
+                goto fail;
+            }
+        if (header->num_extra_channels) {
+            header->extra_channel_info =
+                av_calloc(header->num_extra_channels + 1, sizeof(JpegXLExtraChannelInfo));
+            for (uint32_t i = 0; i < header->num_extra_channels; i++) {
+                status = jpegxl_parse_extra_channel_info(jxlr, header->extra_channel_info + i, 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 = jpegxl_u32(jxlr, (uint32_t[]){0, 524288, 1048576, 2097152}, (uint32_t[]){19, 19, 20, 21});
+                header->white_uy = jpegxl_u32(jxlr, (uint32_t[]){0, 524288, 1048576, 2097152}, (uint32_t[]){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 = jpegxl_u32(jxlr, (uint32_t[]){0, 524288, 1048576, 2097152}, (uint32_t[]){19, 19, 20, 21});
+                header->red_uy = jpegxl_u32(jxlr, (uint32_t[]){0, 524288, 1048576, 2097152}, (uint32_t[]){19, 19, 20, 21});
+                header->green_ux = jpegxl_u32(jxlr, (uint32_t[]){0, 524288, 1048576, 2097152}, (uint32_t[]){19, 19, 20, 21});
+                header->green_uy = jpegxl_u32(jxlr, (uint32_t[]){0, 524288, 1048576, 2097152}, (uint32_t[]){19, 19, 20, 21});
+                header->blue_ux = jpegxl_u32(jxlr, (uint32_t[]){0, 524288, 1048576, 2097152}, (uint32_t[]){19, 19, 20, 21});
+                header->blue_uy = jpegxl_u32(jxlr, (uint32_t[]){0, 524288, 1048576, 2097152}, (uint32_t[]){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;
+            }
+        }
+
+        /* lazy && works with this macro */
+        if (extra_fields && !jxl_bits(1)) {
+            header->intensity_target = jpegxl_f16(jxlr);
+            header->min_nits = jpegxl_f16(jxlr);
+            header->relative_to_max_display = jxl_bits(1);
+            header->linear_below = jpegxl_f16(jxlr);
+        } else {
+            header->intensity_target = 255;
+        }
+
+        header->extensions = jpegxl_u64(jxlr);
+        if (header->extensions) {
+            header->extension_bits = av_calloc(64, sizeof(uint64_t));
+            if (!header->extension_bits) {
+                av_log(avctx, AV_LOG_ERROR, "Could not allocate extension bit array");
+                status = AVERROR(ENOMEM);
+                goto fail;
+            }
+            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);
+
+    /* lazy && works with this macro */
+    if (!header->default_transform && header->xyb_encoded && !jxl_bits(1)) {
+        header->opsin_inverse_matrix = av_malloc_array(16, sizeof(float));
+        if (!header->opsin_inverse_matrix) {
+            av_log(avctx, AV_LOG_ERROR, "Could not allocate Opsin Inverse Matrix");
+            status = AVERROR(ENOMEM);
+            goto fail;
+        }
+        for (int i = 0; i < 16; i++) {
+            header->opsin_inverse_matrix[i] = jpegxl_f16(jxlr);
+        }
+    }
+
+    if (!header->default_transform) {
+        header->cw_mask = jxl_bits(3);
+    }
+
+    if (header->cw_mask & 1) {
+        header->up2_weight = av_malloc_array(15, sizeof(float));
+        if (!header->up2_weight) {
+            av_log(avctx, AV_LOG_ERROR, "Could not allocate up2_weight");
+            status = AVERROR(ENOMEM);
+            goto fail;
+        }
+        for (int i = 0; i < 15; i++) {
+            header->up2_weight[i] = jpegxl_f16(jxlr);
+        }
+    }
+    if (header->cw_mask & 2) {
+        header->up4_weight = av_malloc_array(55, sizeof(float));
+        if (!header->up2_weight) {
+            av_log(avctx, AV_LOG_ERROR, "Could not allocate up4_weight");
+            status = AVERROR(ENOMEM);
+            goto fail;
+        }
+        for (int i = 0; i < 55; i++) {
+            header->up4_weight[i] = jpegxl_f16(jxlr);
+        }
+    }
+    if (header->cw_mask & 4) {
+        header->up8_weight = av_malloc_array(210, sizeof(float));
+        if (!header->up8_weight) {
+            av_log(avctx, AV_LOG_ERROR, "Could not allocate up8_weight");
+            status = AVERROR(ENOMEM);
+            goto fail;
+        }
+        for (int i = 0; i < 210; i++) {
+            header->up8_weight[i] = jpegxl_f16(jxlr);
+        }
+    }
+
+    /* zero pad to byte */
+    if (jxl_bits(7 - ((jxlr->bits_read - 1) % 8))) {
+        jxl_parse_err("zero padding to byte");
+        goto fail;
+    }
+
+    /* bytes consumed > buflen */
+    if ((jxlr->bits_read + 1) / 8 - 1 > jxlr->buflen) {
+        jxl_parse_err("unexpected end of file");
+        goto fail;
+    }
+
+    *headerp = header;
+    return 0;
+
+fail:
+    jpegxl_free_header(header);
+    if (status >= 0 && (jxlr->bits_read + 1) / 8 - 1 > jxlr->buflen)
+        return FFMIN(jxlr->bits_read, INT_MAX);
+    if (status > 0)
+        return -status;
+    return status || -1;
+}
+
+int avpriv_jpegxl_verify_codestream_header(void *avctx, uint8_t *buf, size_t buflen, int level)
+{
+    JpegXLParseContext jxlri;
+    JpegXLHeader *header = NULL;
+    int status;
+    jpegxl_init_pc(&jxlri, buf, buflen);
+    status = jpegxl_parse_codestream_header(avctx, &jxlri, &header, level);
+    if (header)
+        jpegxl_free_header(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 = NULL;
+    int next = END_NOT_FOUND, container = 0, status = 0;
+    size_t 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 == FF_JPEGXL_CONTAINER_SIGNATURE_BE)
+                container = 1;
+            if ((state64 & 0xFFFF) == FF_JPEGXL_CODESTREAM_SIGNATURE_BE
+                    || state64 == FF_JPEGXL_CONTAINER_SIGNATURE_BE) {
+                jxlr->pc.frame_start_found = 1;
+                break;
+            }
+        }
+        jxlr->pc.state64 = state64;
+    }
+
+    if (jxlr->pc.frame_start_found && s1->pict_type == AV_PICTURE_TYPE_NONE) {
+        jpegxl_init_pc(jxlr, buf, buf_size);
+        if (container) {
+            for (;;) {
+                uint64_t size = 0;
+                uint32_t tag = 0;
+                for (int k = 0; k < 4; k++)
+                    size = (size << 8) | jxl_bits(8);
+                for (int k = 0; k < 4; k++)
+                    tag = (tag << 8) | jxl_bits(8);
+                if (tag == MKBETAG('j','x','l','p')) {
+                    jxl_bits(32);
+                    break;
+                }
+                if (tag == MKBETAG('j','x','l','c'))
+                    break;
+                if (size == 1) {
+                    size = 0;
+                    for (int k = 0; k < 8; k++)
+                        size = (size << 8) | jxl_bits(8);
+                    if (size > INT_MAX)
+                        break;
+                    size -= 8;
+                }
+                if (jxlr->bits_read / 8 > buf_size)
+                    break;
+            }
+        }
+        status = jpegxl_parse_codestream_header(NULL, jxlr, &header, 5);
+        if (status == 0) {
+            /* parsed successfully */
+            s1->pict_type = AV_PICTURE_TYPE_I;
+            s1->key_frame = 1;
+            s1->width = avctx->width = avctx->coded_width = header->width;
+            s1->height = avctx->height = avctx->coded_height = header->height;
+            s1->format = avctx->pix_fmt = jpegxl_header_get_pixfmt(header);
+            jxlr->pc.frame_start_found = 1;
+        }
+        if (header)
+            jpegxl_free_header(header);
+        header = NULL;
+    }
+
+    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;
+    *poutbuf_size = buf_size;
+
+    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,
+};
+
+#else /* CONFIG_JPEGXL_PARSER */
+
+int avpriv_jpegxl_verify_codestream_header(void *avctx, uint8_t *buf, size_t buflen, int level)
+{
+    /* parser disabled at compile-time */
+    return AVERROR(ENOSYS);
+}
+
+#endif /* CONFIG_JPEGXL_PARSER */
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 580b099b36..e2499b505b 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -28,8 +28,8 @@
 #include "libavutil/version.h"
 
 #define LIBAVCODEC_VERSION_MAJOR  59
-#define LIBAVCODEC_VERSION_MINOR  15
-#define LIBAVCODEC_VERSION_MICRO 101
+#define LIBAVCODEC_VERSION_MINOR  16
+#define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \
