ffmpeg-libwav1c.patch

diff --git a/configure b/configure
index 998b0292b8..46e00888ae 100755
--- a/configure
+++ b/configure
@@ -282,6 +282,7 @@ External library support:
   --enable-libssh          enable SFTP protocol via libssh [no]
   --enable-libsvtav1       enable AV1 encoding via SVT [no]
   --enable-libsvtjpegxs    enable JPEGXS encoding/decoding via SVT [no]
+  --enable-libwav1c        enable AV1 encoding via wav1c [no]
   --enable-libtensorflow   enable TensorFlow as a DNN module backend
                            for DNN based filters like sr [no]
   --enable-libtesseract    enable Tesseract, needed for ocr filter [no]
@@ -2026,6 +2027,7 @@ EXTERNAL_LIBRARY_LIST="
     libssh
     libsvtav1
     libsvtjpegxs
+    libwav1c
     libtensorflow
     libtesseract
     libtheora
@@ -3730,6 +3732,7 @@ libspeex_encoder_deps="libspeex"
 libspeex_encoder_select="audio_frame_queue"
 libsvtav1_encoder_deps="libsvtav1"
 libsvtjpegxs_encoder_deps="libsvtjpegxs"
+libwav1c_encoder_deps="libwav1c"
 libsvtjpegxs_decoder_deps="libsvtjpegxs"
 libsvtav1_encoder_select="dovi_rpuenc"
 libtheora_encoder_deps="libtheora"
@@ -7282,6 +7285,7 @@ enabled libspeex          && require_pkg_config libspeex speex speex/speex.h spe
 enabled libsrt            && require_pkg_config libsrt "srt >= 1.3.0" srt/srt.h srt_socket
 enabled libsvtav1         && require_pkg_config libsvtav1 "SvtAv1Enc >= 0.9.0" EbSvtAv1Enc.h svt_av1_enc_init_handle
 enabled libsvtjpegxs      && require_pkg_config libsvtjpegxs "SvtJpegxs >= 0.10.0" SvtJpegxsEnc.h svt_jpeg_xs_encoder_init
+enabled libwav1c          && require libwav1c wav1c.h wav1c_encoder_new -lwav1c_ffi
 enabled libtensorflow     && require libtensorflow tensorflow/c/c_api.h TF_Version -ltensorflow
 enabled libtesseract      && require_pkg_config libtesseract tesseract tesseract/capi.h TessBaseAPICreate
 enabled libtheora         && require libtheora theora/theoraenc.h th_info_init -ltheoraenc -ltheoradec -logg
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 3d60347a19..96358857da 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -1207,6 +1207,7 @@ OBJS-$(CONFIG_LIBSPEEX_DECODER)           += libspeexdec.o
 OBJS-$(CONFIG_LIBSPEEX_ENCODER)           += libspeexenc.o
 OBJS-$(CONFIG_LIBSVTAV1_ENCODER)          += libsvtav1.o
 OBJS-$(CONFIG_LIBSVTJPEGXS_DECODER)       += libsvtjpegxsdec.o
+OBJS-$(CONFIG_LIBWAV1C_ENCODER)           += libwav1c.o
 OBJS-$(CONFIG_LIBSVTJPEGXS_ENCODER)       += libsvtjpegxsenc.o
 OBJS-$(CONFIG_LIBTHEORA_ENCODER)          += libtheoraenc.o
 OBJS-$(CONFIG_LIBTWOLAME_ENCODER)         += libtwolame.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 042b07c895..d19aa5fec6 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -816,6 +816,7 @@ extern const FFCodec ff_libspeex_encoder;
 extern const FFCodec ff_libspeex_decoder;
 extern const FFCodec ff_libsvtav1_encoder;
 extern const FFCodec ff_libsvtjpegxs_encoder;
+extern const FFCodec ff_libwav1c_encoder;
 extern const FFCodec ff_libsvtjpegxs_decoder;
 extern const FFCodec ff_libtheora_encoder;
 extern const FFCodec ff_libtwolame_encoder;
diff --git a/libavcodec/libwav1c.c b/libavcodec/libwav1c.c
new file mode 100644
index 0000000000..6372549309
--- /dev/null
+++ b/libavcodec/libwav1c.c
@@ -0,0 +1,248 @@
+/*
+ * wav1c AV1 encoder wrapper for FFmpeg
+ *
+ * Copyright (c) 2026 Rafael Caricio
+ *
+ * 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <wav1c.h>
+
+#include "libavutil/imgutils.h"
+#include "libavutil/mem.h"
+#include "libavutil/opt.h"
+
+#include "avcodec.h"
+#include "codec_internal.h"
+#include "encode.h"
+
+typedef enum {
+  WAV1C_EOS_NOT_REACHED = 0,
+  WAV1C_EOS_SENT,
+  WAV1C_EOS_RECEIVED,
+} Wav1cEosStatus;
+
+typedef struct Wav1cContext {
+  AVClass *class;
+  Wav1cEncoder *encoder;
+  AVFrame *frame;
+  Wav1cEosStatus eos_flag;
+
+  int base_q_idx;
+  int b_frames;
+  int gop_size;
+  int64_t dts_counter;
+} Wav1cContext;
+
+static av_cold int wav1c_init(AVCodecContext *avctx) {
+  Wav1cContext *ctx = avctx->priv_data;
+  Wav1cConfig cfg;
+  const uint8_t *hdr_data;
+  size_t hdr_size;
+
+  cfg.base_q_idx = ctx->base_q_idx;
+  cfg.keyint = avctx->gop_size > 0 ? avctx->gop_size : 250;
+  cfg.target_bitrate = avctx->bit_rate > 0 ? avctx->bit_rate : 0;
+  cfg.b_frames = ctx->b_frames;
+  cfg.gop_size = ctx->gop_size > 0 ? ctx->gop_size : 3;
+
+  if (avctx->framerate.num > 0 && avctx->framerate.den > 0)
+    cfg.fps = (double)avctx->framerate.num / avctx->framerate.den;
+  else if (avctx->time_base.num > 0 && avctx->time_base.den > 0)
+    cfg.fps = (double)avctx->time_base.den / avctx->time_base.num;
+  else
+    cfg.fps = 25.0;
+
+  ctx->encoder = wav1c_encoder_new(avctx->width, avctx->height, &cfg);
+  if (!ctx->encoder) {
+    av_log(avctx, AV_LOG_ERROR, "Failed to create wav1c encoder\n");
+    return AVERROR(EINVAL);
+  }
+
+  if (avctx->flags & AV_CODEC_FLAG_GLOBAL_HEADER) {
+    hdr_size = wav1c_encoder_headers(ctx->encoder, &hdr_data);
+    if (hdr_size > 0) {
+      avctx->extradata = av_mallocz(hdr_size + AV_INPUT_BUFFER_PADDING_SIZE);
+      if (!avctx->extradata) {
+        av_log(avctx, AV_LOG_ERROR, "Cannot allocate extradata\n");
+        return AVERROR(ENOMEM);
+      }
+      memcpy(avctx->extradata, hdr_data, hdr_size);
+      avctx->extradata_size = hdr_size;
+    }
+  }
+
+  ctx->frame = av_frame_alloc();
+  if (!ctx->frame)
+    return AVERROR(ENOMEM);
+
+  ctx->eos_flag = WAV1C_EOS_NOT_REACHED;
+  ctx->dts_counter = 0;
+
+  return 0;
+}
+
+static int wav1c_send_frame(AVCodecContext *avctx, const AVFrame *frame) {
+  Wav1cContext *ctx = avctx->priv_data;
+  int ret;
+  size_t y_size, uv_size;
+
+  if (!frame) {
+    if (ctx->eos_flag == WAV1C_EOS_SENT)
+      return 0;
+    wav1c_encoder_flush(ctx->encoder);
+    ctx->eos_flag = WAV1C_EOS_SENT;
+    return 0;
+  }
+
+  y_size = (size_t)frame->linesize[0] * avctx->height;
+  uv_size = (size_t)frame->linesize[1] * ((avctx->height + 1) / 2);
+
+  ret = wav1c_encoder_send_frame(
+      ctx->encoder, frame->data[0], y_size, frame->data[1], uv_size,
+      frame->data[2], uv_size, frame->linesize[0], frame->linesize[1]);
+  if (ret < 0) {
+    av_log(avctx, AV_LOG_ERROR, "Error sending frame to wav1c encoder\n");
+    return AVERROR_EXTERNAL;
+  }
+
+  return 0;
+}
+
+static int wav1c_receive_packet(AVCodecContext *avctx, AVPacket *pkt) {
+  Wav1cContext *ctx = avctx->priv_data;
+  AVFrame *frame = ctx->frame;
+  Wav1cPacket *wav1c_pkt;
+  int ret;
+
+  if (ctx->eos_flag == WAV1C_EOS_RECEIVED)
+    return AVERROR_EOF;
+
+  ret = ff_encode_get_frame(avctx, frame);
+  if (ret < 0 && ret != AVERROR_EOF)
+    return ret;
+  if (ret == AVERROR_EOF)
+    frame = NULL;
+
+  ret = wav1c_send_frame(avctx, frame);
+  if (ret < 0)
+    return ret;
+  av_frame_unref(ctx->frame);
+
+  wav1c_pkt = wav1c_encoder_receive_packet(ctx->encoder);
+  if (!wav1c_pkt) {
+    if (ctx->eos_flag == WAV1C_EOS_SENT) {
+      ctx->eos_flag = WAV1C_EOS_RECEIVED;
+      return AVERROR_EOF;
+    }
+    return AVERROR(EAGAIN);
+  }
+
+  ret = av_new_packet(pkt, wav1c_pkt->size);
+  if (ret < 0) {
+    wav1c_packet_free(wav1c_pkt);
+    return ret;
+  }
+
+  memcpy(pkt->data, wav1c_pkt->data, wav1c_pkt->size);
+  pkt->pts = ctx->dts_counter;
+  pkt->dts = ctx->dts_counter;
+  ctx->dts_counter++;
+
+  if (wav1c_pkt->is_keyframe)
+    pkt->flags |= AV_PKT_FLAG_KEY;
+
+  wav1c_packet_free(wav1c_pkt);
+
+  return 0;
+}
+
+static av_cold int wav1c_close(AVCodecContext *avctx) {
+  Wav1cContext *ctx = avctx->priv_data;
+
+  if (ctx->encoder) {
+    wav1c_encoder_free(ctx->encoder);
+    ctx->encoder = NULL;
+  }
+
+  av_frame_free(&ctx->frame);
+
+  return 0;
+}
+
+#define OFFSET(x) offsetof(Wav1cContext, x)
+#define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
+
+static const AVOption wav1c_options[] = {
+    {"wav1c-q",
+     "Quantizer (0-255, lower is higher quality)",
+     OFFSET(base_q_idx),
+     AV_OPT_TYPE_INT,
+     {.i64 = 128},
+     0,
+     255,
+     VE},
+    {"wav1c-b-frames",
+     "Enable B-frame encoding (experimental)",
+     OFFSET(b_frames),
+     AV_OPT_TYPE_BOOL,
+     {.i64 = 0},
+     0,
+     1,
+     VE},
+    {"wav1c-gop-size",
+     "Mini-GOP size for B-frame batching",
+     OFFSET(gop_size),
+     AV_OPT_TYPE_INT,
+     {.i64 = 3},
+     2,
+     16,
+     VE},
+    {NULL},
+};
+
+static const AVClass wav1c_class = {
+    .class_name = "libwav1c",
+    .item_name = av_default_item_name,
+    .option = wav1c_options,
+    .version = LIBAVUTIL_VERSION_INT,
+};
+
+static const FFCodecDefault wav1c_defaults[] = {
+    {"b", "0"},
+    {"g", "250"},
+    {NULL},
+};
+
+const FFCodec ff_libwav1c_encoder = {
+    .p.name = "libwav1c",
+    CODEC_LONG_NAME("wav1c AV1 encoder"),
+    .priv_data_size = sizeof(Wav1cContext),
+    .p.type = AVMEDIA_TYPE_VIDEO,
+    .p.id = AV_CODEC_ID_AV1,
+    .init = wav1c_init,
+    FF_CODEC_RECEIVE_PACKET_CB(wav1c_receive_packet),
+    .close = wav1c_close,
+    .p.capabilities = AV_CODEC_CAP_DELAY,
+    .caps_internal =
+        FF_CODEC_CAP_NOT_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
+    CODEC_PIXFMTS(AV_PIX_FMT_YUV420P),
+    .color_ranges = AVCOL_RANGE_MPEG,
+    .p.priv_class = &wav1c_class,
+    .defaults = wav1c_defaults,
+    .p.wrapper_name = "libwav1c",
+};