/*
  * Copyright (c) 2006 Paul Richards <paul.richards@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

  * @brief Theora encoder using libtheora.
  * @author Paul Richards <paul.richards@gmail.com>

  *
  * A lot of this is copy / paste from other output codecs in
  * libavcodec or pure guesswork (or both).
  *
  * I have used t_ prefixes on variables which are libtheora types
  * and o_ prefixes on variables which are libogg types.
  */
 

 /* FFmpeg includes */

 #include "libavutil/common.h"

 #include "libavutil/intreadwrite.h"

 #include "libavutil/pixdesc.h"

 #include "libavutil/log.h"

 #include "libavutil/base64.h"

 #include "avcodec.h"

 #include "internal.h"

 
 /* libtheora includes */

 #include <theora/theoraenc.h>

 typedef struct TheoraContext {

     th_enc_ctx *t_state;

     uint8_t    *stats;
     int         stats_size;
     int         stats_offset;

     int         uv_hshift;
     int         uv_vshift;

     int         keyframe_mask;

 } TheoraContext;
 

 /** Concatenate an ogg_packet into the extradata. */

 static int concatenate_packet(unsigned int* offset,
                               AVCodecContext* avc_context,
                               const ogg_packet* packet)

 {

     const char* message = NULL;

     int newsize = avc_context->extradata_size + 2 + packet->bytes;

     int err = AVERROR_INVALIDDATA;

 
     if (packet->bytes < 0) {
         message = "ogg_packet has negative size";
     } else if (packet->bytes > 0xffff) {
         message = "ogg_packet is larger than 65535 bytes";
     } else if (newsize < avc_context->extradata_size) {
         message = "extradata_size would overflow";
     } else {

         if ((err = av_reallocp(&avc_context->extradata, newsize)) < 0) {
             avc_context->extradata_size = 0;

             message = "av_realloc failed";

         }

     }

     if (message) {

         av_log(avc_context, AV_LOG_ERROR, "concatenate_packet failed: %s\n", message);

         return err;

     }
 
     avc_context->extradata_size = newsize;

     AV_WB16(avc_context->extradata + (*offset), packet->bytes);
     *offset += 2;

     memcpy(avc_context->extradata + (*offset), packet->packet, packet->bytes);

     (*offset) += packet->bytes;
     return 0;
 }
 

 static int get_stats(AVCodecContext *avctx, int eos)
 {

 #ifdef TH_ENCCTL_2PASS_OUT

     TheoraContext *h = avctx->priv_data;
     uint8_t *buf;
     int bytes;
 
     bytes = th_encode_ctl(h->t_state, TH_ENCCTL_2PASS_OUT, &buf, sizeof(buf));
     if (bytes < 0) {
         av_log(avctx, AV_LOG_ERROR, "Error getting first pass stats\n");

         return AVERROR_EXTERNAL;

     }
     if (!eos) {
         h->stats = av_fast_realloc(h->stats, &h->stats_size,
                                    h->stats_offset + bytes);
         memcpy(h->stats + h->stats_offset, buf, bytes);
         h->stats_offset += bytes;
     } else {

         int b64_size = AV_BASE64_SIZE(h->stats_offset);

         // libtheora generates a summary header at the end
         memcpy(h->stats, buf, bytes);
         avctx->stats_out = av_malloc(b64_size);

         if (!avctx->stats_out)
             return AVERROR(ENOMEM);

         av_base64_encode(avctx->stats_out, b64_size, h->stats, h->stats_offset);
     }
     return 0;

 #else
     av_log(avctx, AV_LOG_ERROR, "libtheora too old to support 2pass\n");

     return AVERROR(ENOSUP);

 #endif

 }
 
 // libtheora won't read the entire buffer we give it at once, so we have to
 // repeatedly submit it...
 static int submit_stats(AVCodecContext *avctx)
 {

 #ifdef TH_ENCCTL_2PASS_IN

     TheoraContext *h = avctx->priv_data;
     int bytes;
     if (!h->stats) {
         if (!avctx->stats_in) {
             av_log(avctx, AV_LOG_ERROR, "No statsfile for second pass\n");

             return AVERROR(EINVAL);

         }
         h->stats_size = strlen(avctx->stats_in) * 3/4;
         h->stats      = av_malloc(h->stats_size);
         h->stats_size = av_base64_decode(h->stats, avctx->stats_in, h->stats_size);
     }
     while (h->stats_size - h->stats_offset > 0) {
         bytes = th_encode_ctl(h->t_state, TH_ENCCTL_2PASS_IN,
                               h->stats + h->stats_offset,
                               h->stats_size - h->stats_offset);
         if (bytes < 0) {
             av_log(avctx, AV_LOG_ERROR, "Error submitting stats\n");

             return AVERROR_EXTERNAL;

         }
         if (!bytes)
             return 0;
         h->stats_offset += bytes;
     }
     return 0;

 #else
     av_log(avctx, AV_LOG_ERROR, "libtheora too old to support 2pass\n");

     return AVERROR(ENOSUP);

 #endif

 }
 

 static av_cold int encode_init(AVCodecContext* avc_context)

 {

     th_info t_info;
     th_comment t_comment;

     ogg_packet o_packet;
     unsigned int offset;
     TheoraContext *h = avc_context->priv_data;

     uint32_t gop_size = avc_context->gop_size;

     int ret;

 
     /* Set up the theora_info struct */

     th_info_init(&t_info);
     t_info.frame_width  = FFALIGN(avc_context->width,  16);
     t_info.frame_height = FFALIGN(avc_context->height, 16);
     t_info.pic_width    = avc_context->width;
     t_info.pic_height   = avc_context->height;
     t_info.pic_x        = 0;
     t_info.pic_y        = 0;

     /* Swap numerator and denominator as time_base in AVCodecContext gives the
      * time period between frames, but theora_info needs the framerate.  */

     t_info.fps_numerator   = avc_context->time_base.den;

     t_info.fps_denominator = avc_context->time_base.num;

     if (avc_context->sample_aspect_ratio.num) {

         t_info.aspect_numerator   = avc_context->sample_aspect_ratio.num;

         t_info.aspect_denominator = avc_context->sample_aspect_ratio.den;
     } else {

         t_info.aspect_numerator   = 1;

         t_info.aspect_denominator = 1;
     }

 
     if (avc_context->color_primaries == AVCOL_PRI_BT470M)
         t_info.colorspace = TH_CS_ITU_REC_470M;
     else if (avc_context->color_primaries == AVCOL_PRI_BT470BG)
         t_info.colorspace = TH_CS_ITU_REC_470BG;
     else
         t_info.colorspace = TH_CS_UNSPECIFIED;

     if (avc_context->pix_fmt == AV_PIX_FMT_YUV420P)

         t_info.pixel_fmt = TH_PF_420;

     else if (avc_context->pix_fmt == AV_PIX_FMT_YUV422P)

         t_info.pixel_fmt = TH_PF_422;

     else if (avc_context->pix_fmt == AV_PIX_FMT_YUV444P)

         t_info.pixel_fmt = TH_PF_444;
     else {
         av_log(avc_context, AV_LOG_ERROR, "Unsupported pix_fmt\n");

         return AVERROR(EINVAL);

     }
     avcodec_get_chroma_sub_sample(avc_context->pix_fmt, &h->uv_hshift, &h->uv_vshift);

     if (avc_context->flags & CODEC_FLAG_QSCALE) {

         /* Clip global_quality in QP units to the [0 - 10] range
            to be consistent with the libvorbis implementation.
            Theora accepts a quality parameter which is an int value in
            the [0 - 63] range.
         */

         t_info.quality        = av_clipf(avc_context->global_quality / (float)FF_QP2LAMBDA, 0, 10) * 6.3;

         t_info.target_bitrate = 0;
     } else {
         t_info.target_bitrate = avc_context->bit_rate;

         t_info.quality        = 0;

     }
 

     /* Now initialise libtheora */

     h->t_state = th_encode_alloc(&t_info);
     if (!h->t_state) {

         av_log(avc_context, AV_LOG_ERROR, "theora_encode_init failed\n");

         return AVERROR_EXTERNAL;

     }
 

     h->keyframe_mask = (1 << t_info.keyframe_granule_shift) - 1;

     /* Clear up theora_info struct */

     th_info_clear(&t_info);
 
     if (th_encode_ctl(h->t_state, TH_ENCCTL_SET_KEYFRAME_FREQUENCY_FORCE,
                       &gop_size, sizeof(gop_size))) {
         av_log(avc_context, AV_LOG_ERROR, "Error setting GOP size\n");

         return AVERROR_EXTERNAL;

     }

     // need to enable 2 pass (via TH_ENCCTL_2PASS_) before encoding headers
     if (avc_context->flags & CODEC_FLAG_PASS1) {

         if ((ret = get_stats(avc_context, 0)) < 0)
             return ret;

     } else if (avc_context->flags & CODEC_FLAG_PASS2) {

         if ((ret = submit_stats(avc_context)) < 0)
             return ret;

     }
 

     /*
         Output first header packet consisting of theora
         header, comment, and tables.
 
         Each one is prefixed with a 16bit size, then they

         are concatenated together into libavcodec's extradata.

     */
     offset = 0;
 

     /* Headers */
     th_comment_init(&t_comment);

     while (th_encode_flushheader(h->t_state, &t_comment, &o_packet))

         if ((ret = concatenate_packet(&offset, avc_context, &o_packet)) < 0)
             return ret;

 
     th_comment_clear(&t_comment);

 
     /* Set up the output AVFrame */

     avc_context->coded_frame = av_frame_alloc();

 
     return 0;
 }
 

 static int encode_frame(AVCodecContext* avc_context, AVPacket *pkt,
                         const AVFrame *frame, int *got_packet)

 {

     th_ycbcr_buffer t_yuv_buffer;

     TheoraContext *h = avc_context->priv_data;
     ogg_packet o_packet;

     int result, i, ret;

     // EOS, finish and get 1st pass stats if applicable
     if (!frame) {
         th_encode_packetout(h->t_state, 1, &o_packet);
         if (avc_context->flags & CODEC_FLAG_PASS1)

             if ((ret = get_stats(avc_context, 1)) < 0)
                 return ret;

         return 0;
     }
 

     /* Copy planes to the theora yuv_buffer */

     for (i = 0; i < 3; i++) {

         t_yuv_buffer[i].width  = FFALIGN(avc_context->width,  16) >> (i && h->uv_hshift);
         t_yuv_buffer[i].height = FFALIGN(avc_context->height, 16) >> (i && h->uv_vshift);

         t_yuv_buffer[i].stride = frame->linesize[i];
         t_yuv_buffer[i].data   = frame->data[i];

     }
 

     if (avc_context->flags & CODEC_FLAG_PASS2)

         if ((ret = submit_stats(avc_context)) < 0)
             return ret;

     /* Now call into theora_encode_YUVin */

     result = th_encode_ycbcr_in(h->t_state, t_yuv_buffer);

     if (result) {

         const char* message;
         switch (result) {

         case -1:
             message = "differing frame sizes";
             break;

         case TH_EINVAL:

             message = "encoder is not ready or is finished";
             break;
         default:
             message = "unknown reason";
             break;

         }
         av_log(avc_context, AV_LOG_ERROR, "theora_encode_YUVin failed (%s) [%d]\n", message, result);

         return AVERROR_EXTERNAL;

     }
 

     if (avc_context->flags & CODEC_FLAG_PASS1)

         if ((ret = get_stats(avc_context, 0)) < 0)
             return ret;

     /* Pick up returned ogg_packet */

     result = th_encode_packetout(h->t_state, 0, &o_packet);

     switch (result) {

     case 0:
         /* No packet is ready */
         return 0;
     case 1:
         /* Success, we have a packet */
         break;
     default:
         av_log(avc_context, AV_LOG_ERROR, "theora_encode_packetout failed [%d]\n", result);

         return AVERROR_EXTERNAL;

     }
 
     /* Copy ogg_packet content out to buffer */

     if ((ret = ff_alloc_packet2(avc_context, pkt, o_packet.bytes)) < 0)

         return ret;
     memcpy(pkt->data, o_packet.packet, o_packet.bytes);

     // HACK: assumes no encoder delay, this is true until libtheora becomes

     // multithreaded (which will be disabled unless explicitly requested)

     pkt->pts = pkt->dts = frame->pts;

     avc_context->coded_frame->key_frame = !(o_packet.granulepos & h->keyframe_mask);

     if (avc_context->coded_frame->key_frame)
         pkt->flags |= AV_PKT_FLAG_KEY;
     *got_packet = 1;

     return 0;

 }
 

 static av_cold int encode_close(AVCodecContext* avc_context)

 {
     TheoraContext *h = avc_context->priv_data;
 

     th_encode_free(h->t_state);

     av_freep(&h->stats);

     av_freep(&avc_context->coded_frame);

     av_freep(&avc_context->stats_out);

     av_freep(&avc_context->extradata);
     avc_context->extradata_size = 0;
 

     return 0;

 }
 

 /** AVCodec struct exposed to libavcodec */

 AVCodec ff_libtheora_encoder = {

     .name           = "libtheora",

     .long_name      = NULL_IF_CONFIG_SMALL("libtheora Theora"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_THEORA,

     .priv_data_size = sizeof(TheoraContext),

     .init           = encode_init,
     .close          = encode_close,
     .encode2        = encode_frame,
     .capabilities   = CODEC_CAP_DELAY, // needed to get the statsfile summary

     .pix_fmts       = (const enum AVPixelFormat[]){
         AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_NONE

     },

 };