/*
  * Copyright (c) 2010, Google, Inc.
  *
  * 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
  * VP8 encoder support via libvpx
  */
 
 #define VPX_DISABLE_CTRL_TYPECHECKS 1
 #define VPX_CODEC_DISABLE_COMPAT    1
 #include <vpx/vpx_encoder.h>
 #include <vpx/vp8cx.h>
 
 #include "avcodec.h"

 #include "internal.h"

 #include "libavutil/base64.h"

 #include "libavutil/mathematics.h"

 #include "libavutil/opt.h"

 
 /**
  * Portion of struct vpx_codec_cx_pkt from vpx_encoder.h.
  * One encoded frame returned from the library.
  */
 struct FrameListData {

     void *buf;                       /**< compressed data buffer */
     size_t sz;                       /**< length of compressed data */
     int64_t pts;                     /**< time stamp to show frame

                                           (in timebase units) */

     unsigned long duration;          /**< duration to show frame

                                           (in timebase units) */

     uint32_t flags;                  /**< flags for this frame */

     struct FrameListData *next;
 };
 
 typedef struct VP8EncoderContext {

     AVClass *class;

     struct vpx_codec_ctx encoder;
     struct vpx_image rawimg;
     struct vpx_fixed_buf twopass_stats;

     int deadline; //i.e., RT/GOOD/BEST

     struct FrameListData *coded_frame_list;

     int cpu_used;

     /**
      * VP8 specific flags, see VP8F_* below.
      */
     int flags;
 #define VP8F_ERROR_RESILIENT 0x00000001 ///< Enable measures appropriate for streaming over lossy links
 #define VP8F_AUTO_ALT_REF    0x00000002 ///< Enable automatic alternate reference frame generation
 

     int auto_alt_ref;

 
     int arnr_max_frames;
     int arnr_strength;
     int arnr_type;

     int lag_in_frames;

     int error_resilient;

     int crf;

 } VP8Context;
 
 /** String mappings for enum vp8e_enc_control_id */
 static const char *ctlidstr[] = {
     [VP8E_UPD_ENTROPY]           = "VP8E_UPD_ENTROPY",
     [VP8E_UPD_REFERENCE]         = "VP8E_UPD_REFERENCE",
     [VP8E_USE_REFERENCE]         = "VP8E_USE_REFERENCE",
     [VP8E_SET_ROI_MAP]           = "VP8E_SET_ROI_MAP",
     [VP8E_SET_ACTIVEMAP]         = "VP8E_SET_ACTIVEMAP",
     [VP8E_SET_SCALEMODE]         = "VP8E_SET_SCALEMODE",
     [VP8E_SET_CPUUSED]           = "VP8E_SET_CPUUSED",
     [VP8E_SET_ENABLEAUTOALTREF]  = "VP8E_SET_ENABLEAUTOALTREF",
     [VP8E_SET_NOISE_SENSITIVITY] = "VP8E_SET_NOISE_SENSITIVITY",
     [VP8E_SET_SHARPNESS]         = "VP8E_SET_SHARPNESS",
     [VP8E_SET_STATIC_THRESHOLD]  = "VP8E_SET_STATIC_THRESHOLD",
     [VP8E_SET_TOKEN_PARTITIONS]  = "VP8E_SET_TOKEN_PARTITIONS",
     [VP8E_GET_LAST_QUANTIZER]    = "VP8E_GET_LAST_QUANTIZER",
     [VP8E_SET_ARNR_MAXFRAMES]    = "VP8E_SET_ARNR_MAXFRAMES",
     [VP8E_SET_ARNR_STRENGTH]     = "VP8E_SET_ARNR_STRENGTH",
     [VP8E_SET_ARNR_TYPE]         = "VP8E_SET_ARNR_TYPE",

     [VP8E_SET_CQ_LEVEL]          = "VP8E_SET_CQ_LEVEL",

 };
 
 static av_cold void log_encoder_error(AVCodecContext *avctx, const char *desc)
 {
     VP8Context *ctx = avctx->priv_data;
     const char *error  = vpx_codec_error(&ctx->encoder);
     const char *detail = vpx_codec_error_detail(&ctx->encoder);
 
     av_log(avctx, AV_LOG_ERROR, "%s: %s\n", desc, error);
     if (detail)
         av_log(avctx, AV_LOG_ERROR, "  Additional information: %s\n", detail);
 }
 
 static av_cold void dump_enc_cfg(AVCodecContext *avctx,
                                  const struct vpx_codec_enc_cfg *cfg)
 {
     int width = -30;
     int level = AV_LOG_DEBUG;
 
     av_log(avctx, level, "vpx_codec_enc_cfg\n");
     av_log(avctx, level, "generic settings\n"
            "  %*s%u\n  %*s%u\n  %*s%u\n  %*s%u\n  %*s%u\n"
            "  %*s{%u/%u}\n  %*s%u\n  %*s%d\n  %*s%u\n",
            width, "g_usage:",           cfg->g_usage,
            width, "g_threads:",         cfg->g_threads,
            width, "g_profile:",         cfg->g_profile,
            width, "g_w:",               cfg->g_w,
            width, "g_h:",               cfg->g_h,
            width, "g_timebase:",        cfg->g_timebase.num, cfg->g_timebase.den,
            width, "g_error_resilient:", cfg->g_error_resilient,
            width, "g_pass:",            cfg->g_pass,
            width, "g_lag_in_frames:",   cfg->g_lag_in_frames);
     av_log(avctx, level, "rate control settings\n"
            "  %*s%u\n  %*s%u\n  %*s%u\n  %*s%u\n"
            "  %*s%d\n  %*s%p(%zu)\n  %*s%u\n",
            width, "rc_dropframe_thresh:",   cfg->rc_dropframe_thresh,
            width, "rc_resize_allowed:",     cfg->rc_resize_allowed,
            width, "rc_resize_up_thresh:",   cfg->rc_resize_up_thresh,
            width, "rc_resize_down_thresh:", cfg->rc_resize_down_thresh,
            width, "rc_end_usage:",          cfg->rc_end_usage,
            width, "rc_twopass_stats_in:",   cfg->rc_twopass_stats_in.buf, cfg->rc_twopass_stats_in.sz,
            width, "rc_target_bitrate:",     cfg->rc_target_bitrate);
     av_log(avctx, level, "quantizer settings\n"
            "  %*s%u\n  %*s%u\n",
            width, "rc_min_quantizer:", cfg->rc_min_quantizer,
            width, "rc_max_quantizer:", cfg->rc_max_quantizer);
     av_log(avctx, level, "bitrate tolerance\n"
            "  %*s%u\n  %*s%u\n",
            width, "rc_undershoot_pct:", cfg->rc_undershoot_pct,
            width, "rc_overshoot_pct:",  cfg->rc_overshoot_pct);
     av_log(avctx, level, "decoder buffer model\n"
             "  %*s%u\n  %*s%u\n  %*s%u\n",
             width, "rc_buf_sz:",         cfg->rc_buf_sz,
             width, "rc_buf_initial_sz:", cfg->rc_buf_initial_sz,
             width, "rc_buf_optimal_sz:", cfg->rc_buf_optimal_sz);
     av_log(avctx, level, "2 pass rate control settings\n"
            "  %*s%u\n  %*s%u\n  %*s%u\n",
            width, "rc_2pass_vbr_bias_pct:",       cfg->rc_2pass_vbr_bias_pct,
            width, "rc_2pass_vbr_minsection_pct:", cfg->rc_2pass_vbr_minsection_pct,
            width, "rc_2pass_vbr_maxsection_pct:", cfg->rc_2pass_vbr_maxsection_pct);
     av_log(avctx, level, "keyframing settings\n"
            "  %*s%d\n  %*s%u\n  %*s%u\n",
            width, "kf_mode:",     cfg->kf_mode,
            width, "kf_min_dist:", cfg->kf_min_dist,
            width, "kf_max_dist:", cfg->kf_max_dist);
     av_log(avctx, level, "\n");
 }
 
 static void coded_frame_add(void *list, struct FrameListData *cx_frame)
 {
     struct FrameListData **p = list;
 
     while (*p != NULL)
         p = &(*p)->next;
     *p = cx_frame;
     cx_frame->next = NULL;
 }
 
 static av_cold void free_coded_frame(struct FrameListData *cx_frame)
 {
     av_freep(&cx_frame->buf);
     av_freep(&cx_frame);
 }
 
 static av_cold void free_frame_list(struct FrameListData *list)
 {
     struct FrameListData *p = list;
 
     while (p) {
         list = list->next;
         free_coded_frame(p);
         p = list;
     }
 }
 
 static av_cold int codecctl_int(AVCodecContext *avctx,
                                 enum vp8e_enc_control_id id, int val)
 {
     VP8Context *ctx = avctx->priv_data;
     char buf[80];
     int width = -30;
     int res;
 
     snprintf(buf, sizeof(buf), "%s:", ctlidstr[id]);
     av_log(avctx, AV_LOG_DEBUG, "  %*s%d\n", width, buf, val);
 
     res = vpx_codec_control(&ctx->encoder, id, val);
     if (res != VPX_CODEC_OK) {
         snprintf(buf, sizeof(buf), "Failed to set %s codec control",
                  ctlidstr[id]);
         log_encoder_error(avctx, buf);
     }
 
     return res == VPX_CODEC_OK ? 0 : AVERROR(EINVAL);
 }
 
 static av_cold int vp8_free(AVCodecContext *avctx)
 {
     VP8Context *ctx = avctx->priv_data;
 
     vpx_codec_destroy(&ctx->encoder);
     av_freep(&ctx->twopass_stats.buf);
     av_freep(&avctx->coded_frame);
     av_freep(&avctx->stats_out);
     free_frame_list(ctx->coded_frame_list);
     return 0;
 }
 
 static av_cold int vp8_init(AVCodecContext *avctx)
 {
     VP8Context *ctx = avctx->priv_data;
     const struct vpx_codec_iface *iface = &vpx_codec_vp8_cx_algo;
     struct vpx_codec_enc_cfg enccfg;
     int res;
 
     av_log(avctx, AV_LOG_INFO, "%s\n", vpx_codec_version_str());
     av_log(avctx, AV_LOG_VERBOSE, "%s\n", vpx_codec_build_config());
 
     if ((res = vpx_codec_enc_config_default(iface, &enccfg, 0)) != VPX_CODEC_OK) {
         av_log(avctx, AV_LOG_ERROR, "Failed to get config: %s\n",
                vpx_codec_err_to_string(res));
         return AVERROR(EINVAL);
     }
     dump_enc_cfg(avctx, &enccfg);
 
     enccfg.g_w            = avctx->width;
     enccfg.g_h            = avctx->height;
     enccfg.g_timebase.num = avctx->time_base.num;
     enccfg.g_timebase.den = avctx->time_base.den;
     enccfg.g_threads      = avctx->thread_count;

 #if FF_API_X264_GLOBAL_OPTS

     if(avctx->rc_lookahead >= 0)
         enccfg.g_lag_in_frames= FFMIN(avctx->rc_lookahead, 25);  //0-25, avoids init failure

     if (ctx->lag_in_frames >= 0)
         enccfg.g_lag_in_frames = ctx->lag_in_frames;

 #else

     enccfg.g_lag_in_frames= ctx->lag_in_frames;

 #endif

 
     if (avctx->flags & CODEC_FLAG_PASS1)
         enccfg.g_pass = VPX_RC_FIRST_PASS;
     else if (avctx->flags & CODEC_FLAG_PASS2)
         enccfg.g_pass = VPX_RC_LAST_PASS;
     else
         enccfg.g_pass = VPX_RC_ONE_PASS;
 
     if (avctx->rc_min_rate == avctx->rc_max_rate &&
         avctx->rc_min_rate == avctx->bit_rate)
         enccfg.rc_end_usage = VPX_CBR;

 #if FF_API_X264_GLOBAL_OPTS
     else if (avctx->crf || ctx->crf > 0)
 #else
     else if (ctx->crf)
 #endif

         enccfg.rc_end_usage = VPX_CQ;

     enccfg.rc_target_bitrate = av_rescale_rnd(avctx->bit_rate, 1, 1000,
                                               AV_ROUND_NEAR_INF);

     if (avctx->qmin > 0)
         enccfg.rc_min_quantizer = avctx->qmin;
     if (avctx->qmax > 0)
         enccfg.rc_max_quantizer = avctx->qmax;

     enccfg.rc_dropframe_thresh = avctx->frame_skip_threshold;

     //0-100 (0 => CBR, 100 => VBR)
     enccfg.rc_2pass_vbr_bias_pct           = round(avctx->qcompress * 100);
     enccfg.rc_2pass_vbr_minsection_pct     =

         avctx->rc_min_rate * 100LL / avctx->bit_rate;

     if (avctx->rc_max_rate)
         enccfg.rc_2pass_vbr_maxsection_pct =

             avctx->rc_max_rate * 100LL / avctx->bit_rate;

     if (avctx->rc_buffer_size)
         enccfg.rc_buf_sz         =

             avctx->rc_buffer_size * 1000LL / avctx->bit_rate;

     if (avctx->rc_initial_buffer_occupancy)
         enccfg.rc_buf_initial_sz =

             avctx->rc_initial_buffer_occupancy * 1000LL / avctx->bit_rate;

     enccfg.rc_buf_optimal_sz     = enccfg.rc_buf_sz * 5 / 6;

     enccfg.rc_undershoot_pct     = round(avctx->rc_buffer_aggressivity * 100);

     //_enc_init() will balk if kf_min_dist differs from max w/VPX_KF_AUTO

     if (avctx->keyint_min >= 0 && avctx->keyint_min == avctx->gop_size)

         enccfg.kf_min_dist = avctx->keyint_min;

     if (avctx->gop_size >= 0)
         enccfg.kf_max_dist = avctx->gop_size;

 
     if (enccfg.g_pass == VPX_RC_FIRST_PASS)
         enccfg.g_lag_in_frames = 0;
     else if (enccfg.g_pass == VPX_RC_LAST_PASS) {
         int decode_size;
 
         if (!avctx->stats_in) {
             av_log(avctx, AV_LOG_ERROR, "No stats file for second pass\n");
             return AVERROR_INVALIDDATA;
         }
 
         ctx->twopass_stats.sz  = strlen(avctx->stats_in) * 3 / 4;
         ctx->twopass_stats.buf = av_malloc(ctx->twopass_stats.sz);
         if (!ctx->twopass_stats.buf) {
             av_log(avctx, AV_LOG_ERROR,
                    "Stat buffer alloc (%zu bytes) failed\n",
                    ctx->twopass_stats.sz);
             return AVERROR(ENOMEM);
         }
         decode_size = av_base64_decode(ctx->twopass_stats.buf, avctx->stats_in,
                                        ctx->twopass_stats.sz);
         if (decode_size < 0) {
             av_log(avctx, AV_LOG_ERROR, "Stat buffer decode failed\n");
             return AVERROR_INVALIDDATA;
         }
 
         ctx->twopass_stats.sz      = decode_size;
         enccfg.rc_twopass_stats_in = ctx->twopass_stats;
     }
 

     /* 0-3: For non-zero values the encoder increasingly optimizes for reduced
        complexity playback on low powered devices at the expense of encode
        quality. */
    if (avctx->profile != FF_PROFILE_UNKNOWN)
        enccfg.g_profile = avctx->profile;

     enccfg.g_error_resilient = ctx->error_resilient || ctx->flags & VP8F_ERROR_RESILIENT;

     dump_enc_cfg(avctx, &enccfg);
     /* Construct Encoder Context */
     res = vpx_codec_enc_init(&ctx->encoder, iface, &enccfg, 0);
     if (res != VPX_CODEC_OK) {
         log_encoder_error(avctx, "Failed to initialize encoder");
         return AVERROR(EINVAL);
     }
 
     //codec control failures are currently treated only as warnings
     av_log(avctx, AV_LOG_DEBUG, "vpx_codec_control\n");

     if (ctx->cpu_used != INT_MIN)
         codecctl_int(avctx, VP8E_SET_CPUUSED,          ctx->cpu_used);

     if (ctx->flags & VP8F_AUTO_ALT_REF)
         ctx->auto_alt_ref = 1;

     if (ctx->auto_alt_ref >= 0)
         codecctl_int(avctx, VP8E_SET_ENABLEAUTOALTREF, ctx->auto_alt_ref);
     if (ctx->arnr_max_frames >= 0)
         codecctl_int(avctx, VP8E_SET_ARNR_MAXFRAMES,   ctx->arnr_max_frames);
     if (ctx->arnr_strength >= 0)
         codecctl_int(avctx, VP8E_SET_ARNR_STRENGTH,    ctx->arnr_strength);
     if (ctx->arnr_type >= 0)
         codecctl_int(avctx, VP8E_SET_ARNR_TYPE,        ctx->arnr_type);

     codecctl_int(avctx, VP8E_SET_NOISE_SENSITIVITY, avctx->noise_reduction);

     codecctl_int(avctx, VP8E_SET_TOKEN_PARTITIONS,  av_log2(avctx->slices));

     codecctl_int(avctx, VP8E_SET_STATIC_THRESHOLD,  avctx->mb_threshold);

 #if FF_API_X264_GLOBAL_OPTS

     codecctl_int(avctx, VP8E_SET_CQ_LEVEL,          (int)avctx->crf);

     if (ctx->crf >= 0)
         codecctl_int(avctx, VP8E_SET_CQ_LEVEL,      ctx->crf);
 #else
     codecctl_int(avctx, VP8E_SET_CQ_LEVEL,          ctx->crf);
 #endif

 
     av_log(avctx, AV_LOG_DEBUG, "Using deadline: %d\n", ctx->deadline);

 
     //provide dummy value to initialize wrapper, values will be updated each _encode()
     vpx_img_wrap(&ctx->rawimg, VPX_IMG_FMT_I420, avctx->width, avctx->height, 1,
                  (unsigned char*)1);
 
     avctx->coded_frame = avcodec_alloc_frame();
     if (!avctx->coded_frame) {
         av_log(avctx, AV_LOG_ERROR, "Error allocating coded frame\n");
         vp8_free(avctx);
         return AVERROR(ENOMEM);
     }
     return 0;
 }
 
 static inline void cx_pktcpy(struct FrameListData *dst,
                              const struct vpx_codec_cx_pkt *src)
 {
     dst->pts      = src->data.frame.pts;
     dst->duration = src->data.frame.duration;
     dst->flags    = src->data.frame.flags;
     dst->sz       = src->data.frame.sz;
     dst->buf      = src->data.frame.buf;
 }
 
 /**
  * Store coded frame information in format suitable for return from encode().
  *
  * Write buffer information from @a cx_frame to @a buf & @a buf_size.
  * Timing/frame details to @a coded_frame.
  * @return Frame size written to @a buf on success
  * @return AVERROR(EINVAL) on error
  */
 static int storeframe(AVCodecContext *avctx, struct FrameListData *cx_frame,
                       uint8_t *buf, int buf_size, AVFrame *coded_frame)
 {
     if ((int) cx_frame->sz <= buf_size) {
         buf_size = cx_frame->sz;
         memcpy(buf, cx_frame->buf, buf_size);
         coded_frame->pts       = cx_frame->pts;
         coded_frame->key_frame = !!(cx_frame->flags & VPX_FRAME_IS_KEY);
 
         if (coded_frame->key_frame)

             coded_frame->pict_type = AV_PICTURE_TYPE_I;

         else

             coded_frame->pict_type = AV_PICTURE_TYPE_P;

     } else {
         av_log(avctx, AV_LOG_ERROR,
                "Compressed frame larger than storage provided! (%zu/%d)\n",
                cx_frame->sz, buf_size);
         return AVERROR(EINVAL);
     }
     return buf_size;
 }
 
 /**
  * Queue multiple output frames from the encoder, returning the front-most.
  * In cases where vpx_codec_get_cx_data() returns more than 1 frame append
  * the frame queue. Return the head frame if available.
  * @return Stored frame size
  * @return AVERROR(EINVAL) on output size error
  * @return AVERROR(ENOMEM) on coded frame queue data allocation error
  */
 static int queue_frames(AVCodecContext *avctx, uint8_t *buf, int buf_size,
                         AVFrame *coded_frame)
 {
     VP8Context *ctx = avctx->priv_data;
     const struct vpx_codec_cx_pkt *pkt;
     const void *iter = NULL;
     int size = 0;
 
     if (ctx->coded_frame_list) {
         struct FrameListData *cx_frame = ctx->coded_frame_list;
         /* return the leading frame if we've already begun queueing */
         size = storeframe(avctx, cx_frame, buf, buf_size, coded_frame);
         if (size < 0)
             return AVERROR(EINVAL);
         ctx->coded_frame_list = cx_frame->next;
         free_coded_frame(cx_frame);
     }
 
     /* consume all available output from the encoder before returning. buffers
        are only good through the next vpx_codec call */
     while ((pkt = vpx_codec_get_cx_data(&ctx->encoder, &iter))) {
         switch (pkt->kind) {
         case VPX_CODEC_CX_FRAME_PKT:
             if (!size) {
                 struct FrameListData cx_frame;
 
                 /* avoid storing the frame when the list is empty and we haven't yet
                    provided a frame for output */
                 assert(!ctx->coded_frame_list);
                 cx_pktcpy(&cx_frame, pkt);
                 size = storeframe(avctx, &cx_frame, buf, buf_size, coded_frame);
                 if (size < 0)
                     return AVERROR(EINVAL);
             } else {
                 struct FrameListData *cx_frame =
                     av_malloc(sizeof(struct FrameListData));
 
                 if (!cx_frame) {
                     av_log(avctx, AV_LOG_ERROR,
                            "Frame queue element alloc failed\n");
                     return AVERROR(ENOMEM);
                 }
                 cx_pktcpy(cx_frame, pkt);
                 cx_frame->buf = av_malloc(cx_frame->sz);
 
                 if (!cx_frame->buf) {
                     av_log(avctx, AV_LOG_ERROR,
                            "Data buffer alloc (%zu bytes) failed\n",
                            cx_frame->sz);

                     av_free(cx_frame);

                     return AVERROR(ENOMEM);
                 }
                 memcpy(cx_frame->buf, pkt->data.frame.buf, pkt->data.frame.sz);
                 coded_frame_add(&ctx->coded_frame_list, cx_frame);
             }
             break;
         case VPX_CODEC_STATS_PKT: {
             struct vpx_fixed_buf *stats = &ctx->twopass_stats;

             stats->buf = av_realloc_f(stats->buf, 1,
                                       stats->sz + pkt->data.twopass_stats.sz);

             if (!stats->buf) {
                 av_log(avctx, AV_LOG_ERROR, "Stat buffer realloc failed\n");
                 return AVERROR(ENOMEM);
             }
             memcpy((uint8_t*)stats->buf + stats->sz,
                    pkt->data.twopass_stats.buf, pkt->data.twopass_stats.sz);
             stats->sz += pkt->data.twopass_stats.sz;
             break;
         }
         case VPX_CODEC_PSNR_PKT: //FIXME add support for CODEC_FLAG_PSNR
         case VPX_CODEC_CUSTOM_PKT:
             //ignore unsupported/unrecognized packet types
             break;
         }
     }
 
     return size;
 }
 
 static int vp8_encode(AVCodecContext *avctx, uint8_t *buf, int buf_size,
                       void *data)
 {
     VP8Context *ctx = avctx->priv_data;
     AVFrame *frame = data;
     struct vpx_image *rawimg = NULL;
     int64_t timestamp = 0;
     int res, coded_size;
 
     if (frame) {
         rawimg                      = &ctx->rawimg;
         rawimg->planes[VPX_PLANE_Y] = frame->data[0];
         rawimg->planes[VPX_PLANE_U] = frame->data[1];
         rawimg->planes[VPX_PLANE_V] = frame->data[2];
         rawimg->stride[VPX_PLANE_Y] = frame->linesize[0];
         rawimg->stride[VPX_PLANE_U] = frame->linesize[1];
         rawimg->stride[VPX_PLANE_V] = frame->linesize[2];
         timestamp                   = frame->pts;
     }
 
     res = vpx_codec_encode(&ctx->encoder, rawimg, timestamp,
                            avctx->ticks_per_frame, 0, ctx->deadline);
     if (res != VPX_CODEC_OK) {
         log_encoder_error(avctx, "Error encoding frame");
         return AVERROR_INVALIDDATA;
     }
     coded_size = queue_frames(avctx, buf, buf_size, avctx->coded_frame);
 
     if (!frame && avctx->flags & CODEC_FLAG_PASS1) {

         unsigned int b64_size = AV_BASE64_SIZE(ctx->twopass_stats.sz);

 
         avctx->stats_out = av_malloc(b64_size);
         if (!avctx->stats_out) {
             av_log(avctx, AV_LOG_ERROR, "Stat buffer alloc (%d bytes) failed\n",
                    b64_size);
             return AVERROR(ENOMEM);
         }
         av_base64_encode(avctx->stats_out, b64_size, ctx->twopass_stats.buf,
                          ctx->twopass_stats.sz);
     }
     return coded_size;
 }
 

 #define OFFSET(x) offsetof(VP8Context, x)

 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM

 static const AVOption options[] = {

     { "cpu-used",        "Quality/Speed ratio modifier",           OFFSET(cpu_used),        AV_OPT_TYPE_INT, {INT_MIN}, INT_MIN, INT_MAX, VE},

     { "auto-alt-ref",    "Enable use of alternate reference "

                          "frames (2-pass only)",                   OFFSET(auto_alt_ref),    AV_OPT_TYPE_INT, {-1},      -1,      1,       VE},

     { "lag-in-frames",   "Number of frames to look ahead for "

                          "alternate reference frame selection",    OFFSET(lag_in_frames),   AV_OPT_TYPE_INT, {-1},      -1,      INT_MAX, VE},
     { "arnr-maxframes",  "altref noise reduction max frame count", OFFSET(arnr_max_frames), AV_OPT_TYPE_INT, {-1},      -1,      INT_MAX, VE},
     { "arnr-strength",   "altref noise reduction filter strength", OFFSET(arnr_strength),   AV_OPT_TYPE_INT, {-1},      -1,      INT_MAX, VE},
     { "arnr-type",       "altref noise reduction filter type",     OFFSET(arnr_type),       AV_OPT_TYPE_INT, {-1},      -1,      INT_MAX, VE, "arnr_type"},
     { "backward",        NULL, 0, AV_OPT_TYPE_CONST, {1}, 0, 0, VE, "arnr_type" },
     { "forward",         NULL, 0, AV_OPT_TYPE_CONST, {2}, 0, 0, VE, "arnr_type" },
     { "centered",        NULL, 0, AV_OPT_TYPE_CONST, {3}, 0, 0, VE, "arnr_type" },
     { "deadline",        "Time to spend encoding, in microseconds.", OFFSET(deadline),      AV_OPT_TYPE_INT, {VPX_DL_GOOD_QUALITY}, INT_MIN, INT_MAX, VE, "quality"},
     { "best",            NULL, 0, AV_OPT_TYPE_CONST, {VPX_DL_BEST_QUALITY}, 0, 0, VE, "quality"},
     { "good",            NULL, 0, AV_OPT_TYPE_CONST, {VPX_DL_GOOD_QUALITY}, 0, 0, VE, "quality"},
     { "realtime",        NULL, 0, AV_OPT_TYPE_CONST, {VPX_DL_REALTIME},     0, 0, VE, "quality"},
     { "error-resilient", "Error resilience configuration", OFFSET(error_resilient), AV_OPT_TYPE_FLAGS, {0}, INT_MIN, INT_MAX, VE, "er"},

 #ifdef VPX_ERROR_RESILIENT_DEFAULT

     { "default",         "Improve resiliency against losses of whole frames", 0, AV_OPT_TYPE_CONST, {VPX_ERROR_RESILIENT_DEFAULT}, 0, 0, VE, "er"},

     { "partitions",      "The frame partitions are independently decodable "
                          "by the bool decoder, meaning that partitions can be decoded even "
                          "though earlier partitions have been lost. Note that intra predicition"

                          " is still done over the partition boundary.",       0, AV_OPT_TYPE_CONST, {VPX_ERROR_RESILIENT_PARTITIONS}, 0, 0, VE, "er"},

 #endif

 {"speed", "", offsetof(VP8Context, cpu_used), AV_OPT_TYPE_INT, {.dbl = 3}, -16, 16, VE},
 {"quality", "", offsetof(VP8Context, deadline), AV_OPT_TYPE_INT, {.dbl = VPX_DL_GOOD_QUALITY}, INT_MIN, INT_MAX, VE, "quality"},

 {"vp8flags", "", offsetof(VP8Context, flags), FF_OPT_TYPE_FLAGS, {.dbl = 0}, 0, UINT_MAX, VE, "flags"},
 {"error_resilient", "enable error resilience", 0, FF_OPT_TYPE_CONST, {.dbl = VP8F_ERROR_RESILIENT}, INT_MIN, INT_MAX, VE, "flags"},
 {"altref", "enable use of alternate reference frames (VP8/2-pass only)", 0, FF_OPT_TYPE_CONST, {.dbl = VP8F_AUTO_ALT_REF}, INT_MIN, INT_MAX, VE, "flags"},

 {"arnr_max_frames", "altref noise reduction max frame count", offsetof(VP8Context, arnr_max_frames), AV_OPT_TYPE_INT, {.dbl = 0}, 0, 15, VE},
 {"arnr_strength", "altref noise reduction filter strength", offsetof(VP8Context, arnr_strength), AV_OPT_TYPE_INT, {.dbl = 3}, 0, 6, VE},
 {"arnr_type", "altref noise reduction filter type", offsetof(VP8Context, arnr_type), AV_OPT_TYPE_INT, {.dbl = 3}, 1, 3, VE},

 #if FF_API_X264_GLOBAL_OPTS

 {"rc_lookahead", "Number of frames to look ahead for alternate reference frame selection", offsetof(VP8Context, lag_in_frames), AV_OPT_TYPE_INT, {.dbl = -1}, -1, 25, VE},
 {"crf", "Select the quality for constant quality mode", offsetof(VP8Context, crf), AV_OPT_TYPE_INT, {.dbl = -1}, -1, 63, VE},

 #else

 {"rc_lookahead", "Number of frames to look ahead for alternate reference frame selection", offsetof(VP8Context, lag_in_frames), AV_OPT_TYPE_INT, {.dbl = 25}, 0, 25, VE},
 {"crf", "Select the quality for constant quality mode", offsetof(VP8Context, crf), AV_OPT_TYPE_INT, {.dbl = 0}, 0, 63, VE},

 #endif
 {NULL}

 };
 
 static const AVClass class = {
     .class_name = "libvpx encoder",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 

 static const AVCodecDefault defaults[] = {
     { "qmin",             "-1" },
     { "qmax",             "-1" },
     { "g",                "-1" },
     { "keyint_min",       "-1" },
     { NULL },
 };
 

 AVCodec ff_libvpx_encoder = {

     .name           = "libvpx",
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = CODEC_ID_VP8,
     .priv_data_size = sizeof(VP8Context),
     .init           = vp8_init,
     .encode         = vp8_encode,
     .close          = vp8_free,

     .capabilities   = CODEC_CAP_DELAY | CODEC_CAP_AUTO_THREADS,

     .pix_fmts = (const enum PixelFormat[]){PIX_FMT_YUV420P, PIX_FMT_NONE},
     .long_name = NULL_IF_CONFIG_SMALL("libvpx VP8"),

     .priv_class = &class,

     .defaults       = defaults,

 };