diff -up firefox-127.0/media/ffvpx/libavcodec/codec_list.c.1667096 firefox-127.0/media/ffvpx/libavcodec/codec_list.c
--- firefox-127.0/media/ffvpx/libavcodec/codec_list.c.1667096	2024-06-06 23:33:57.000000000 +0200
+++ firefox-127.0/media/ffvpx/libavcodec/codec_list.c	2024-06-10 12:42:39.353913204 +0200
@@ -11,6 +11,9 @@ static const FFCodec * const codec_list[
 #if CONFIG_MP3_DECODER
     &ff_mp3_decoder,
 #endif
+#ifdef CONFIG_LIBFDK_AAC
+    &ff_libfdk_aac_decoder,
+#endif
 #if CONFIG_LIBDAV1D
     &ff_libdav1d_decoder,
 #endif
diff -up firefox-127.0/media/ffvpx/libavcodec/libfdk-aacdec.c.1667096 firefox-127.0/media/ffvpx/libavcodec/libfdk-aacdec.c
--- firefox-127.0/media/ffvpx/libavcodec/libfdk-aacdec.c.1667096	2024-06-10 12:42:39.354913201 +0200
+++ firefox-127.0/media/ffvpx/libavcodec/libfdk-aacdec.c	2024-06-10 16:28:30.332367814 +0200
@@ -0,0 +1,498 @@
+/*
+ * AAC decoder wrapper
+ * Copyright (c) 2012 Martin Storsjo
+ *
+ * This file is part of FFmpeg.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <fdk-aac/aacdecoder_lib.h>
+
+#include "libavutil/channel_layout.h"
+#include "libavutil/common.h"
+#include "libavutil/opt.h"
+#include "libavutil/mem.h"
+#include "avcodec.h"
+#include "codec_internal.h"
+#include "decode.h"
+
+#ifdef AACDECODER_LIB_VL0
+#define FDKDEC_VER_AT_LEAST(vl0, vl1) \
+    ((AACDECODER_LIB_VL0 > vl0) || \
+     (AACDECODER_LIB_VL0 == vl0 && AACDECODER_LIB_VL1 >= vl1))
+#else
+#define FDKDEC_VER_AT_LEAST(vl0, vl1) 0
+#endif
+
+#if !FDKDEC_VER_AT_LEAST(2, 5) // < 2.5.10
+#define AAC_PCM_MAX_OUTPUT_CHANNELS AAC_PCM_OUTPUT_CHANNELS
+#endif
+
+enum ConcealMethod {
+    CONCEAL_METHOD_SPECTRAL_MUTING      =  0,
+    CONCEAL_METHOD_NOISE_SUBSTITUTION   =  1,
+    CONCEAL_METHOD_ENERGY_INTERPOLATION =  2,
+    CONCEAL_METHOD_NB,
+};
+
+typedef struct FDKAACDecContext {
+    const AVClass *class;
+    HANDLE_AACDECODER handle;
+    uint8_t *decoder_buffer;
+    int decoder_buffer_size;
+    uint8_t *anc_buffer;
+    int conceal_method;
+    int drc_level;
+    int drc_boost;
+    int drc_heavy;
+    int drc_effect;
+    int drc_cut;
+    int album_mode;
+    int level_limit;
+#if FDKDEC_VER_AT_LEAST(2, 5) // 2.5.10
+    int output_delay_set;
+    int flush_samples;
+    int delay_samples;
+#endif
+    AVChannelLayout downmix_layout;
+} FDKAACDecContext;
+
+
+#define DMX_ANC_BUFFSIZE       128
+#define DECODER_MAX_CHANNELS     8
+#define DECODER_BUFFSIZE      2048 * sizeof(INT_PCM)
+
+#define OFFSET(x) offsetof(FDKAACDecContext, x)
+#define AD AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM
+static const AVOption fdk_aac_dec_options[] = {
+    { "conceal", "Error concealment method", OFFSET(conceal_method), AV_OPT_TYPE_INT, { .i64 = CONCEAL_METHOD_NOISE_SUBSTITUTION }, CONCEAL_METHOD_SPECTRAL_MUTING, CONCEAL_METHOD_NB - 1, AD, "conceal" },
+    { "spectral", "Spectral muting",      0, AV_OPT_TYPE_CONST, { .i64 = CONCEAL_METHOD_SPECTRAL_MUTING },      INT_MIN, INT_MAX, AD, "conceal" },
+    { "noise",    "Noise Substitution",   0, AV_OPT_TYPE_CONST, { .i64 = CONCEAL_METHOD_NOISE_SUBSTITUTION },   INT_MIN, INT_MAX, AD, "conceal" },
+    { "energy",   "Energy Interpolation", 0, AV_OPT_TYPE_CONST, { .i64 = CONCEAL_METHOD_ENERGY_INTERPOLATION }, INT_MIN, INT_MAX, AD, "conceal" },
+    { "drc_boost", "Dynamic Range Control: boost, where [0] is none and [127] is max boost",
+                     OFFSET(drc_boost),      AV_OPT_TYPE_INT,   { .i64 = -1 }, -1, 127, AD, NULL    },
+    { "drc_cut",   "Dynamic Range Control: attenuation factor, where [0] is none and [127] is max compression",
+                     OFFSET(drc_cut),        AV_OPT_TYPE_INT,   { .i64 = -1 }, -1, 127, AD, NULL    },
+    { "drc_level", "Dynamic Range Control: reference level, quantized to 0.25dB steps where [0] is 0dB and [127] is -31.75dB, -1 for auto, and -2 for disabled",
+                     OFFSET(drc_level),      AV_OPT_TYPE_INT,   { .i64 = -1},  -2, 127, AD, NULL    },
+    { "drc_heavy", "Dynamic Range Control: heavy compression, where [1] is on (RF mode) and [0] is off",
+                     OFFSET(drc_heavy),      AV_OPT_TYPE_INT,   { .i64 = -1},  -1, 1,   AD, NULL    },
+#if FDKDEC_VER_AT_LEAST(2, 5) // 2.5.10
+    { "level_limit", "Signal level limiting",
+                     OFFSET(level_limit),    AV_OPT_TYPE_BOOL,  { .i64 = -1 }, -1, 1, AD },
+#endif
+#if FDKDEC_VER_AT_LEAST(3, 0) // 3.0.0
+    { "drc_effect","Dynamic Range Control: effect type, where e.g. [0] is none and [6] is general",
+                     OFFSET(drc_effect),     AV_OPT_TYPE_INT,   { .i64 = -1},  -1, 8,   AD, NULL    },
+#endif
+#if FDKDEC_VER_AT_LEAST(3, 1) // 3.1.0
+    { "album_mode","Dynamic Range Control: album mode, where [0] is off and [1] is on",
+                     OFFSET(album_mode),     AV_OPT_TYPE_INT,   { .i64 = -1},  -1, 1,   AD, NULL    },
+#endif
+    { "downmix", "Request a specific channel layout from the decoder", OFFSET(downmix_layout), AV_OPT_TYPE_CHLAYOUT, {.str = NULL}, .flags = AD },
+    { NULL }
+};
+
+static const AVClass fdk_aac_dec_class = {
+    .class_name = "libfdk-aac decoder",
+    .item_name  = av_default_item_name,
+    .option     = fdk_aac_dec_options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+static int get_stream_info(AVCodecContext *avctx)
+{
+    FDKAACDecContext *s   = avctx->priv_data;
+    CStreamInfo *info     = aacDecoder_GetStreamInfo(s->handle);
+    int channel_counts[0x24] = { 0 };
+    int i, ch_error       = 0;
+    uint64_t ch_layout    = 0;
+
+    if (!info) {
+        av_log(avctx, AV_LOG_ERROR, "Unable to get stream info\n");
+        return AVERROR_UNKNOWN;
+    }
+
+    if (info->sampleRate <= 0) {
+        av_log(avctx, AV_LOG_ERROR, "Stream info not initialized\n");
+        return AVERROR_UNKNOWN;
+    }
+    avctx->sample_rate = info->sampleRate;
+    avctx->frame_size  = info->frameSize;
+#if FDKDEC_VER_AT_LEAST(2, 5) // 2.5.10
+    if (!s->output_delay_set && info->outputDelay) {
+        // Set this only once.
+        s->flush_samples    = info->outputDelay;
+        s->delay_samples    = info->outputDelay;
+        s->output_delay_set = 1;
+    }
+#endif
+
+    for (i = 0; i < info->numChannels; i++) {
+        AUDIO_CHANNEL_TYPE ctype = info->pChannelType[i];
+        if (ctype <= ACT_NONE || ctype >= FF_ARRAY_ELEMS(channel_counts)) {
+            av_log(avctx, AV_LOG_WARNING, "unknown channel type\n");
+            break;
+        }
+        channel_counts[ctype]++;
+    }
+    av_log(avctx, AV_LOG_DEBUG,
+           "%d channels - front:%d side:%d back:%d lfe:%d top:%d\n",
+           info->numChannels,
+           channel_counts[ACT_FRONT], channel_counts[ACT_SIDE],
+           channel_counts[ACT_BACK],  channel_counts[ACT_LFE],
+           channel_counts[ACT_FRONT_TOP] + channel_counts[ACT_SIDE_TOP] +
+           channel_counts[ACT_BACK_TOP]  + channel_counts[ACT_TOP]);
+
+    switch (channel_counts[ACT_FRONT]) {
+    case 4:
+        ch_layout |= AV_CH_LAYOUT_STEREO | AV_CH_FRONT_LEFT_OF_CENTER |
+                     AV_CH_FRONT_RIGHT_OF_CENTER;
+        break;
+    case 3:
+        ch_layout |= AV_CH_LAYOUT_STEREO | AV_CH_FRONT_CENTER;
+        break;
+    case 2:
+        ch_layout |= AV_CH_LAYOUT_STEREO;
+        break;
+    case 1:
+        ch_layout |= AV_CH_FRONT_CENTER;
+        break;
+    default:
+        av_log(avctx, AV_LOG_WARNING,
+               "unsupported number of front channels: %d\n",
+               channel_counts[ACT_FRONT]);
+        ch_error = 1;
+        break;
+    }
+    if (channel_counts[ACT_SIDE] > 0) {
+        if (channel_counts[ACT_SIDE] == 2) {
+            ch_layout |= AV_CH_SIDE_LEFT | AV_CH_SIDE_RIGHT;
+        } else {
+            av_log(avctx, AV_LOG_WARNING,
+                   "unsupported number of side channels: %d\n",
+                   channel_counts[ACT_SIDE]);
+            ch_error = 1;
+        }
+    }
+    if (channel_counts[ACT_BACK] > 0) {
+        switch (channel_counts[ACT_BACK]) {
+        case 3:
+            ch_layout |= AV_CH_BACK_LEFT | AV_CH_BACK_RIGHT | AV_CH_BACK_CENTER;
+            break;
+        case 2:
+            ch_layout |= AV_CH_BACK_LEFT | AV_CH_BACK_RIGHT;
+            break;
+        case 1:
+            ch_layout |= AV_CH_BACK_CENTER;
+            break;
+        default:
+            av_log(avctx, AV_LOG_WARNING,
+                   "unsupported number of back channels: %d\n",
+                   channel_counts[ACT_BACK]);
+            ch_error = 1;
+            break;
+        }
+    }
+    if (channel_counts[ACT_LFE] > 0) {
+        if (channel_counts[ACT_LFE] == 1) {
+            ch_layout |= AV_CH_LOW_FREQUENCY;
+        } else {
+            av_log(avctx, AV_LOG_WARNING,
+                   "unsupported number of LFE channels: %d\n",
+                   channel_counts[ACT_LFE]);
+            ch_error = 1;
+        }
+    }
+
+    av_channel_layout_uninit(&avctx->ch_layout);
+    av_channel_layout_from_mask(&avctx->ch_layout, ch_layout);
+    if (!ch_error && avctx->ch_layout.nb_channels != info->numChannels) {
+        av_log(avctx, AV_LOG_WARNING, "unsupported channel configuration\n");
+        ch_error = 1;
+    }
+    if (ch_error)
+        avctx->ch_layout.order = AV_CHANNEL_ORDER_UNSPEC;
+
+    return 0;
+}
+
+static av_cold int fdk_aac_decode_close(AVCodecContext *avctx)
+{
+    FDKAACDecContext *s = avctx->priv_data;
+
+    if (s->handle)
+        aacDecoder_Close(s->handle);
+    av_freep(&s->decoder_buffer);
+    av_freep(&s->anc_buffer);
+
+    return 0;
+}
+
+static av_cold int fdk_aac_decode_init(AVCodecContext *avctx)
+{
+    FDKAACDecContext *s = avctx->priv_data;
+    AAC_DECODER_ERROR err;
+
+    s->handle = aacDecoder_Open(avctx->extradata_size ? TT_MP4_RAW : TT_MP4_ADTS, 1);
+    if (!s->handle) {
+        av_log(avctx, AV_LOG_ERROR, "Error opening decoder\n");
+        return AVERROR_UNKNOWN;
+    }
+
+    if (avctx->extradata_size) {
+        if ((err = aacDecoder_ConfigRaw(s->handle, &avctx->extradata,
+                                        &avctx->extradata_size)) != AAC_DEC_OK) {
+            av_log(avctx, AV_LOG_ERROR, "Unable to set extradata\n");
+            return AVERROR_INVALIDDATA;
+        }
+    }
+
+    if ((err = aacDecoder_SetParam(s->handle, AAC_CONCEAL_METHOD,
+                                   s->conceal_method)) != AAC_DEC_OK) {
+        av_log(avctx, AV_LOG_ERROR, "Unable to set error concealment method\n");
+        return AVERROR_UNKNOWN;
+    }
+
+#if FF_API_OLD_CHANNEL_LAYOUT
+FF_DISABLE_DEPRECATION_WARNINGS
+    if (avctx->request_channel_layout) {
+        av_channel_layout_uninit(&s->downmix_layout);
+        av_channel_layout_from_mask(&s->downmix_layout, avctx->request_channel_layout);
+    }
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
+    if (s->downmix_layout.nb_channels > 0 &&
+        s->downmix_layout.order != AV_CHANNEL_ORDER_NATIVE) {
+        int downmix_channels = -1;
+
+        switch (s->downmix_layout.u.mask) {
+        case AV_CH_LAYOUT_STEREO:
+        case AV_CH_LAYOUT_STEREO_DOWNMIX:
+            downmix_channels = 2;
+            break;
+        case AV_CH_LAYOUT_MONO:
+            downmix_channels = 1;
+            break;
+        default:
+            av_log(avctx, AV_LOG_WARNING, "Invalid downmix option\n");
+            break;
+        }
+
+        if (downmix_channels != -1) {
+            if (aacDecoder_SetParam(s->handle, AAC_PCM_MAX_OUTPUT_CHANNELS,
+                                    downmix_channels) != AAC_DEC_OK) {
+               av_log(avctx, AV_LOG_WARNING, "Unable to set output channels in the decoder\n");
+            } else {
+               s->anc_buffer = av_malloc(DMX_ANC_BUFFSIZE);
+               if (!s->anc_buffer) {
+                   av_log(avctx, AV_LOG_ERROR, "Unable to allocate ancillary buffer for the decoder\n");
+                   return AVERROR(ENOMEM);
+               }
+               if (aacDecoder_AncDataInit(s->handle, s->anc_buffer, DMX_ANC_BUFFSIZE)) {
+                   av_log(avctx, AV_LOG_ERROR, "Unable to register downmix ancillary buffer in the decoder\n");
+                   return AVERROR_UNKNOWN;
+               }
+            }
+        }
+    }
+
+    if (s->drc_boost != -1) {
+        if (aacDecoder_SetParam(s->handle, AAC_DRC_BOOST_FACTOR, s->drc_boost) != AAC_DEC_OK) {
+            av_log(avctx, AV_LOG_ERROR, "Unable to set DRC boost factor in the decoder\n");
+            return AVERROR_UNKNOWN;
+        }
+    }
+
+    if (s->drc_cut != -1) {
+        if (aacDecoder_SetParam(s->handle, AAC_DRC_ATTENUATION_FACTOR, s->drc_cut) != AAC_DEC_OK) {
+            av_log(avctx, AV_LOG_ERROR, "Unable to set DRC attenuation factor in the decoder\n");
+            return AVERROR_UNKNOWN;
+        }
+    }
+
+    if (s->drc_level != -1) {
+        // This option defaults to -1, i.e. not calling
+        // aacDecoder_SetParam(AAC_DRC_REFERENCE_LEVEL) at all, which defaults
+        // to the level from DRC metadata, if available. The user can set
+        // -drc_level -2, which calls aacDecoder_SetParam(
+        // AAC_DRC_REFERENCE_LEVEL) with a negative value, which then
+        // explicitly disables the feature.
+        if (aacDecoder_SetParam(s->handle, AAC_DRC_REFERENCE_LEVEL, s->drc_level) != AAC_DEC_OK) {
+            av_log(avctx, AV_LOG_ERROR, "Unable to set DRC reference level in the decoder\n");
+            return AVERROR_UNKNOWN;
+        }
+    }
+
+    if (s->drc_heavy != -1) {
+        if (aacDecoder_SetParam(s->handle, AAC_DRC_HEAVY_COMPRESSION, s->drc_heavy) != AAC_DEC_OK) {
+            av_log(avctx, AV_LOG_ERROR, "Unable to set DRC heavy compression in the decoder\n");
+            return AVERROR_UNKNOWN;
+        }
+    }
+
+#if FDKDEC_VER_AT_LEAST(2, 5) // 2.5.10
+    // Setting this parameter to -1 enables the auto behaviour in the library.
+    if (aacDecoder_SetParam(s->handle, AAC_PCM_LIMITER_ENABLE, s->level_limit) != AAC_DEC_OK) {
+        av_log(avctx, AV_LOG_ERROR, "Unable to set in signal level limiting in the decoder\n");
+        return AVERROR_UNKNOWN;
+    }
+#endif
+
+#if FDKDEC_VER_AT_LEAST(3, 0) // 3.0.0
+    if (s->drc_effect != -1) {
+        if (aacDecoder_SetParam(s->handle, AAC_UNIDRC_SET_EFFECT, s->drc_effect) != AAC_DEC_OK) {
+            av_log(avctx, AV_LOG_ERROR, "Unable to set DRC effect type in the decoder\n");
+            return AVERROR_UNKNOWN;
+        }
+    }
+#endif
+
+#if FDKDEC_VER_AT_LEAST(3, 1) // 3.1.0
+    if (s->album_mode != -1) {
+        if (aacDecoder_SetParam(s->handle, AAC_UNIDRC_ALBUM_MODE, s->album_mode) != AAC_DEC_OK) {
+            av_log(avctx, AV_LOG_ERROR, "Unable to set album mode in the decoder\n");
+            return AVERROR_UNKNOWN;
+        }
+    }
+#endif
+
+    avctx->sample_fmt = AV_SAMPLE_FMT_S16;
+
+    s->decoder_buffer_size = DECODER_BUFFSIZE * DECODER_MAX_CHANNELS;
+    s->decoder_buffer = av_malloc(s->decoder_buffer_size);
+    if (!s->decoder_buffer)
+        return AVERROR(ENOMEM);
+
+    return 0;
+}
+
+static int fdk_aac_decode_frame(AVCodecContext *avctx, AVFrame *frame,
+                                int *got_frame_ptr, AVPacket *avpkt)
+{
+    FDKAACDecContext *s = avctx->priv_data;
+    int ret;
+    AAC_DECODER_ERROR err;
+    UINT valid = avpkt->size;
+    UINT flags = 0;
+    int input_offset = 0;
+
+    if (avpkt->size) {
+        err = aacDecoder_Fill(s->handle, &avpkt->data, &avpkt->size, &valid);
+        if (err != AAC_DEC_OK) {
+            av_log(avctx, AV_LOG_ERROR, "aacDecoder_Fill() failed: %x\n", err);
+            return AVERROR_INVALIDDATA;
+        }
+    } else {
+#if FDKDEC_VER_AT_LEAST(2, 5) // 2.5.10
+        /* Handle decoder draining */
+        if (s->flush_samples > 0) {
+            flags |= AACDEC_FLUSH;
+        } else {
+            return AVERROR_EOF;
+        }
+#else
+        return AVERROR_EOF;
+#endif
+    }
+
+    err = aacDecoder_DecodeFrame(s->handle, (INT_PCM *) s->decoder_buffer,
+                                 s->decoder_buffer_size / sizeof(INT_PCM),
+                                 flags);
+    if (err == AAC_DEC_NOT_ENOUGH_BITS) {
+        ret = avpkt->size - valid;
+        goto end;
+    }
+    if (err != AAC_DEC_OK) {
+        av_log(avctx, AV_LOG_ERROR,
+               "aacDecoder_DecodeFrame() failed: %x\n", err);
+        ret = AVERROR_UNKNOWN;
+        goto end;
+    }
+
+    if ((ret = get_stream_info(avctx)) < 0)
+        goto end;
+    frame->nb_samples = avctx->frame_size;
+
+#if FDKDEC_VER_AT_LEAST(2, 5) // 2.5.10
+    if (flags & AACDEC_FLUSH) {
+        // Only return the right amount of samples at the end; if calling the
+        // decoder with AACDEC_FLUSH, it will keep returning frames indefinitely.
+        frame->nb_samples = FFMIN(s->flush_samples, frame->nb_samples);
+        av_log(s, AV_LOG_DEBUG, "Returning %d/%d delayed samples.\n",
+                                frame->nb_samples, s->flush_samples);
+        s->flush_samples -= frame->nb_samples;
+    } else {
+        // Trim off samples from the start to compensate for extra decoder
+        // delay. We could also just adjust the pts, but this avoids
+        // including the extra samples in the output altogether.
+        if (s->delay_samples) {
+            int drop_samples = FFMIN(s->delay_samples, frame->nb_samples);
+            av_log(s, AV_LOG_DEBUG, "Dropping %d/%d delayed samples.\n",
+                                    drop_samples, s->delay_samples);
+            s->delay_samples  -= drop_samples;
+            frame->nb_samples -= drop_samples;
+            input_offset = drop_samples * avctx->ch_layout.nb_channels;
+            if (frame->nb_samples <= 0)
+                return 0;
+        }
+    }
+#endif
+
+    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+        goto end;
+
+    memcpy(frame->extended_data[0], s->decoder_buffer + input_offset,
+           avctx->ch_layout.nb_channels * frame->nb_samples *
+           av_get_bytes_per_sample(avctx->sample_fmt));
+
+    *got_frame_ptr = 1;
+    ret = avpkt->size - valid;
+
+end:
+    return ret;
+}
+
+static av_cold void fdk_aac_decode_flush(AVCodecContext *avctx)
+{
+    FDKAACDecContext *s = avctx->priv_data;
+    AAC_DECODER_ERROR err;
+
+    if (!s->handle)
+        return;
+
+    if ((err = aacDecoder_SetParam(s->handle,
+                                   AAC_TPDEC_CLEAR_BUFFER, 1)) != AAC_DEC_OK)
+        av_log(avctx, AV_LOG_WARNING, "failed to clear buffer when flushing\n");
+}
+
+const FFCodec ff_libfdk_aac_decoder = {
+    .p.name         = "libfdk_aac",
+    CODEC_LONG_NAME("Fraunhofer FDK AAC"),
+    .p.type         = AVMEDIA_TYPE_AUDIO,
+    .p.id           = AV_CODEC_ID_AAC,
+    .priv_data_size = sizeof(FDKAACDecContext),
+    .init           = fdk_aac_decode_init,
+    FF_CODEC_DECODE_CB(fdk_aac_decode_frame),
+    .close          = fdk_aac_decode_close,
+    .flush          = fdk_aac_decode_flush,
+    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF
+#if FDKDEC_VER_AT_LEAST(2, 5) // 2.5.10
+                      | AV_CODEC_CAP_DELAY
+#endif
+    ,
+    .p.priv_class   = &fdk_aac_dec_class,
+    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
+    .p.wrapper_name = "libfdk",
+};
diff -up firefox-127.0/media/ffvpx/libavcodec/moz.build.1667096 firefox-127.0/media/ffvpx/libavcodec/moz.build
--- firefox-127.0/media/ffvpx/libavcodec/moz.build.1667096	2024-06-06 23:33:58.000000000 +0200
+++ firefox-127.0/media/ffvpx/libavcodec/moz.build	2024-06-10 12:42:39.354913201 +0200
@@ -151,6 +151,12 @@ else:
   CXXFLAGS += CONFIG["MOZ_LIBVPX_CFLAGS"]
   OS_LIBS += CONFIG["MOZ_LIBVPX_LIBS"]
 
+if CONFIG['MOZ_FDK_AAC']:
+    SOURCES += [
+        'libfdk-aacdec.c',
+    ]
+    OS_LIBS += CONFIG['MOZ_FDK_AAC_LIBS']
+
 SYMBOLS_FILE = 'avcodec.symbols'
 NoVisibilityFlags()
 
diff -up firefox-127.0/toolkit/moz.configure.1667096 firefox-127.0/toolkit/moz.configure
--- firefox-127.0/toolkit/moz.configure.1667096	2024-06-10 12:42:39.312913316 +0200
+++ firefox-127.0/toolkit/moz.configure	2024-06-10 12:42:39.355913199 +0200
@@ -2412,6 +2412,15 @@ with only_when(compile_environment):
 
     set_config("MOZ_SYSTEM_PNG", True, when="--with-system-png")
 
+# FDK AAC support
+# ==============================================================
+option('--with-system-fdk-aac',
+       help='Use system libfdk-aac (located with pkgconfig)')
+
+system_fdk_aac = pkg_check_modules('MOZ_FDK_AAC', 'fdk-aac',
+                                   when='--with-system-fdk-aac')
+
+set_config('MOZ_FDK_AAC', depends(when=system_fdk_aac)(lambda: True))
 
 # FFmpeg's ffvpx configuration
 # ==============================================================
