text: /*
   * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
   *
   * 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
   */
  
  #include "libavutil/log.h"
  #include "libavutil/opt.h"
  
  #include "avcodec.h"
  #include "bsf.h"
  
  enum RemoveFreq {
      REMOVE_FREQ_KEYFRAME,
      REMOVE_FREQ_ALL,
      REMOVE_FREQ_NONKEYFRAME,
  };
  
  typedef struct RemoveExtradataContext {
      const AVClass *class;
      int freq;
  
      AVCodecParserContext *parser;
      AVCodecContext *avctx;
  } RemoveExtradataContext;
  
  static int remove_extradata(AVBSFContext *ctx, AVPacket *pkt)
  {
      RemoveExtradataContext *s = ctx->priv_data;
  
      int ret;
  
      ret = ff_bsf_get_packet_ref(ctx, pkt);
      if (ret < 0)
          return ret;
  
      if (s->parser && s->parser->parser->split) {
          if (s->freq == REMOVE_FREQ_ALL ||
              (s->freq == REMOVE_FREQ_NONKEYFRAME && !(pkt->flags & AV_PKT_FLAG_KEY)) ||
              (s->freq == REMOVE_FREQ_KEYFRAME && pkt->flags & AV_PKT_FLAG_KEY)) {
              int i = s->parser->parser->split(s->avctx, pkt->data, pkt->size);
              pkt->data += i;
              pkt->size -= i;
          }
      }
  
      return 0;
  }
  
  static int remove_extradata_init(AVBSFContext *ctx)
  {
      RemoveExtradataContext *s = ctx->priv_data;
      int ret;
  
      s->parser = av_parser_init(ctx->par_in->codec_id);
  
      if (s->parser) {
          s->avctx = avcodec_alloc_context3(NULL);
          if (!s->avctx)
              return AVERROR(ENOMEM);
  
          ret = avcodec_parameters_to_context(s->avctx, ctx->par_in);
          if (ret < 0)
              return ret;
      }
  
      return 0;
  }
  
  static void remove_extradata_close(AVBSFContext *ctx)
  {
      RemoveExtradataContext *s = ctx->priv_data;
  
      avcodec_free_context(&s->avctx);
      av_parser_close(s->parser);
  }
  
  #define OFFSET(x) offsetof(RemoveExtradataContext, x)
  #define FLAGS (AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_BSF_PARAM)
  static const AVOption options[] = {
      { "freq", NULL, OFFSET(freq), AV_OPT_TYPE_INT, { .i64 = REMOVE_FREQ_KEYFRAME }, REMOVE_FREQ_KEYFRAME, REMOVE_FREQ_NONKEYFRAME, FLAGS, "freq" },
          { "k",        NULL, 0, AV_OPT_TYPE_CONST, { .i64 = REMOVE_FREQ_NONKEYFRAME }, .flags = FLAGS, .unit = "freq" },
          { "keyframe", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = REMOVE_FREQ_KEYFRAME }, .flags = FLAGS, .unit = "freq" },
          { "e",        NULL, 0, AV_OPT_TYPE_CONST, { .i64 = REMOVE_FREQ_ALL      }, .flags = FLAGS, .unit = "freq" },
          { "all",      NULL, 0, AV_OPT_TYPE_CONST, { .i64 = REMOVE_FREQ_ALL      }, .flags = FLAGS, .unit = "freq" },
      { NULL },
  };
  
  static const AVClass remove_extradata_class = {
      .class_name = "remove_extradata",
      .item_name  = av_default_item_name,
      .option     = options,
      .version    = LIBAVUTIL_VERSION_INT,
  };
  
  const AVBitStreamFilter ff_remove_extradata_bsf = {
      .name           = "remove_extra",
      .priv_data_size = sizeof(RemoveExtradataContext),
      .priv_class     = &remove_extradata_class,
      .init           = remove_extradata_init,
      .close          = remove_extradata_close,
      .filter         = remove_extradata,
  };
  