libavcodec/extract_extradata_bsf.c - third_party/ffmpeg - Git at Google

 /*
  * 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 <stdint.h>

 #include "libavutil/common.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/log.h"
 #include "libavutil/opt.h"

 #include "avcodec.h"
 #include "av1.h"
 #include "av1_parse.h"
 #include "bsf.h"
 #include "bytestream.h"
 #include "h2645_parse.h"
 #include "h264.h"
 #include "hevc.h"
 #include "vc1_common.h"

 typedef struct ExtractExtradataContext {
     const AVClass *class;

     int (*extract)(AVBSFContext *ctx, AVPacket *pkt,
                    uint8_t **data, int *size);

     /* AV1 specific fields */
     AV1Packet av1_pkt;

     /* H264/HEVC specific fields */
     H2645Packet h2645_pkt;

     /* AVOptions */
     int remove;
 } ExtractExtradataContext;

 static int val_in_array(const int *arr, int len, int val)
 {
     int i;
     for (i = 0; i < len; i++)
         if (arr[i] == val)
             return 1;
     return 0;
 }

 static int extract_extradata_av1(AVBSFContext *ctx, AVPacket *pkt,
                                  uint8_t **data, int *size)
 {
     static const int extradata_obu_types[] = {
         AV1_OBU_SEQUENCE_HEADER, AV1_OBU_METADATA,
     };
     ExtractExtradataContext *s = ctx->priv_data;

     int extradata_size = 0, filtered_size = 0;
     int nb_extradata_obu_types = FF_ARRAY_ELEMS(extradata_obu_types);
     int i, has_seq = 0, ret = 0;

     ret = ff_av1_packet_split(&s->av1_pkt, pkt->data, pkt->size, ctx);
     if (ret < 0)
         return ret;

     for (i = 0; i < s->av1_pkt.nb_obus; i++) {
         AV1OBU *obu = &s->av1_pkt.obus[i];
         if (val_in_array(extradata_obu_types, nb_extradata_obu_types, obu->type)) {
             extradata_size += obu->raw_size;
             if (obu->type == AV1_OBU_SEQUENCE_HEADER)
                 has_seq = 1;
         } else if (s->remove) {
             filtered_size += obu->raw_size;
         }
     }

     if (extradata_size && has_seq) {
         AVBufferRef *filtered_buf = NULL;
         PutByteContext pb_filtered_data, pb_extradata;
         uint8_t *extradata;

         if (s->remove) {
             filtered_buf = av_buffer_alloc(filtered_size + AV_INPUT_BUFFER_PADDING_SIZE);
             if (!filtered_buf) {
                 return AVERROR(ENOMEM);
             }
             memset(filtered_buf->data + filtered_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
         }

         extradata = av_malloc(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
         if (!extradata) {
             av_buffer_unref(&filtered_buf);
             return AVERROR(ENOMEM);
         }
         memset(extradata + extradata_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);

         *data = extradata;
         *size = extradata_size;

         bytestream2_init_writer(&pb_extradata, extradata, extradata_size);
         if (s->remove)
             bytestream2_init_writer(&pb_filtered_data, filtered_buf->data, filtered_size);

         for (i = 0; i < s->av1_pkt.nb_obus; i++) {
             AV1OBU *obu = &s->av1_pkt.obus[i];
             if (val_in_array(extradata_obu_types, nb_extradata_obu_types,
                              obu->type)) {
                 bytestream2_put_bufferu(&pb_extradata, obu->raw_data, obu->raw_size);
             } else if (s->remove) {
                 bytestream2_put_bufferu(&pb_filtered_data, obu->raw_data, obu->raw_size);
             }
         }

         if (s->remove) {
             av_buffer_unref(&pkt->buf);
             pkt->buf  = filtered_buf;
             pkt->data = filtered_buf->data;
             pkt->size = filtered_size;
         }
     }

     return 0;
 }

 static int extract_extradata_h2645(AVBSFContext *ctx, AVPacket *pkt,
                                    uint8_t **data, int *size)
 {
     static const int extradata_nal_types_hevc[] = {
         HEVC_NAL_VPS, HEVC_NAL_SPS, HEVC_NAL_PPS,
     };
     static const int extradata_nal_types_h264[] = {
         H264_NAL_SPS, H264_NAL_PPS,
     };

     ExtractExtradataContext *s = ctx->priv_data;

     int extradata_size = 0, filtered_size = 0;
     const int *extradata_nal_types;
     int nb_extradata_nal_types;
     int i, has_sps = 0, has_vps = 0, ret = 0;

     if (ctx->par_in->codec_id == AV_CODEC_ID_HEVC) {
         extradata_nal_types    = extradata_nal_types_hevc;
         nb_extradata_nal_types = FF_ARRAY_ELEMS(extradata_nal_types_hevc);
     } else {
         extradata_nal_types    = extradata_nal_types_h264;
         nb_extradata_nal_types = FF_ARRAY_ELEMS(extradata_nal_types_h264);
     }

     ret = ff_h2645_packet_split(&s->h2645_pkt, pkt->data, pkt->size,
                                 ctx, 0, 0, ctx->par_in->codec_id, 1, 0);
     if (ret < 0)
         return ret;

     for (i = 0; i < s->h2645_pkt.nb_nals; i++) {
         H2645NAL *nal = &s->h2645_pkt.nals[i];
         if (val_in_array(extradata_nal_types, nb_extradata_nal_types, nal->type)) {
             extradata_size += nal->raw_size + 3;
             if (ctx->par_in->codec_id == AV_CODEC_ID_HEVC) {
                 if (nal->type == HEVC_NAL_SPS) has_sps = 1;
                 if (nal->type == HEVC_NAL_VPS) has_vps = 1;
             } else {
                 if (nal->type == H264_NAL_SPS) has_sps = 1;
             }
         } else if (s->remove) {
             filtered_size += nal->raw_size + 3;
         }
     }

     if (extradata_size &&
         ((ctx->par_in->codec_id == AV_CODEC_ID_HEVC && has_sps && has_vps) ||
          (ctx->par_in->codec_id == AV_CODEC_ID_H264 && has_sps))) {
         AVBufferRef *filtered_buf = NULL;
         PutByteContext pb_filtered_data, pb_extradata;
         uint8_t *extradata;

         if (s->remove) {
             filtered_buf = av_buffer_alloc(filtered_size + AV_INPUT_BUFFER_PADDING_SIZE);
             if (!filtered_buf) {
                 return AVERROR(ENOMEM);
             }
             memset(filtered_buf->data + filtered_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
         }

         extradata = av_malloc(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
         if (!extradata) {
             av_buffer_unref(&filtered_buf);
             return AVERROR(ENOMEM);
         }
         memset(extradata + extradata_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);

         *data = extradata;
         *size = extradata_size;

         bytestream2_init_writer(&pb_extradata, extradata, extradata_size);
         if (s->remove)
             bytestream2_init_writer(&pb_filtered_data, filtered_buf->data, filtered_size);

         for (i = 0; i < s->h2645_pkt.nb_nals; i++) {
             H2645NAL *nal = &s->h2645_pkt.nals[i];
             if (val_in_array(extradata_nal_types, nb_extradata_nal_types,
                              nal->type)) {
                 bytestream2_put_be24u(&pb_extradata, 1); //startcode
                 bytestream2_put_bufferu(&pb_extradata, nal->raw_data, nal->raw_size);
             } else if (s->remove) {
                 bytestream2_put_be24u(&pb_filtered_data, 1); // startcode
                 bytestream2_put_bufferu(&pb_filtered_data, nal->raw_data, nal->raw_size);
             }
         }

         if (s->remove) {
             av_buffer_unref(&pkt->buf);
             pkt->buf  = filtered_buf;
             pkt->data = filtered_buf->data;
             pkt->size = filtered_size;
         }
     }

     return 0;
 }

 static int extract_extradata_vc1(AVBSFContext *ctx, AVPacket *pkt,
                                  uint8_t **data, int *size)
 {
     ExtractExtradataContext *s = ctx->priv_data;
     const uint8_t *ptr = pkt->data, *end = pkt->data + pkt->size;
     uint32_t state = UINT32_MAX;
     int has_extradata = 0, extradata_size = 0;

     while (ptr < end) {
         ptr = avpriv_find_start_code(ptr, end, &state);
         if (state == VC1_CODE_SEQHDR || state == VC1_CODE_ENTRYPOINT) {
             has_extradata = 1;
         } else if (has_extradata && IS_MARKER(state)) {
             extradata_size = ptr - 4 - pkt->data;
             break;
         }
     }

     if (extradata_size) {
         *data = av_malloc(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
         if (!*data)
             return AVERROR(ENOMEM);

         memcpy(*data, pkt->data, extradata_size);
         memset(*data + extradata_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
         *size = extradata_size;

         if (s->remove) {
             pkt->data += extradata_size;
             pkt->size -= extradata_size;
         }
     }

     return 0;
 }

 static int extract_extradata_mpeg12(AVBSFContext *ctx, AVPacket *pkt,
                                      uint8_t **data, int *size)
 {
     ExtractExtradataContext *s = ctx->priv_data;
     uint32_t state = UINT32_MAX;
     int i, found = 0;

     for (i = 0; i < pkt->size; i++) {
         state = (state << 8) | pkt->data[i];
         if (state == 0x1B3)
             found = 1;
         else if (found && state != 0x1B5 && state < 0x200 && state >= 0x100) {
             if (i > 3) {
                 *size = i - 3;
                 *data = av_malloc(*size + AV_INPUT_BUFFER_PADDING_SIZE);
                 if (!*data)
                     return AVERROR(ENOMEM);

                 memcpy(*data, pkt->data, *size);
                 memset(*data + *size, 0, AV_INPUT_BUFFER_PADDING_SIZE);

                 if (s->remove) {
                     pkt->data += *size;
                     pkt->size -= *size;
                 }
             }
             break;
         }
     }
     return 0;
 }

 static int extract_extradata_mpeg4(AVBSFContext *ctx, AVPacket *pkt,
                                    uint8_t **data, int *size)
 {
     ExtractExtradataContext *s = ctx->priv_data;
     const uint8_t *ptr = pkt->data, *end = pkt->data + pkt->size;
     uint32_t state = UINT32_MAX;

     while (ptr < end) {
         ptr = avpriv_find_start_code(ptr, end, &state);
         if (state == 0x1B3 || state == 0x1B6) {
             if (ptr - pkt->data > 4) {
                 *size = ptr - 4 - pkt->data;
                 *data = av_malloc(*size + AV_INPUT_BUFFER_PADDING_SIZE);
                 if (!*data)
                     return AVERROR(ENOMEM);

                 memcpy(*data, pkt->data, *size);
                 memset(*data + *size, 0, AV_INPUT_BUFFER_PADDING_SIZE);

                 if (s->remove) {
                     pkt->data += *size;
                     pkt->size -= *size;
                 }
             }
             break;
         }
     }
     return 0;
 }

 static const struct {
     enum AVCodecID id;
     int (*extract)(AVBSFContext *ctx, AVPacket *pkt,
                    uint8_t **data, int *size);
 } extract_tab[] = {
     { AV_CODEC_ID_AV1,        extract_extradata_av1     },
     { AV_CODEC_ID_AVS2,       extract_extradata_mpeg4   },
     { AV_CODEC_ID_CAVS,       extract_extradata_mpeg4   },
     { AV_CODEC_ID_H264,       extract_extradata_h2645   },
     { AV_CODEC_ID_HEVC,       extract_extradata_h2645   },
     { AV_CODEC_ID_MPEG1VIDEO, extract_extradata_mpeg12  },
     { AV_CODEC_ID_MPEG2VIDEO, extract_extradata_mpeg12  },
     { AV_CODEC_ID_MPEG4,      extract_extradata_mpeg4   },
     { AV_CODEC_ID_VC1,        extract_extradata_vc1     },
 };

 static int extract_extradata_init(AVBSFContext *ctx)
 {
     ExtractExtradataContext *s = ctx->priv_data;
     int i;

     for (i = 0; i < FF_ARRAY_ELEMS(extract_tab); i++) {
         if (extract_tab[i].id == ctx->par_in->codec_id) {
             s->extract = extract_tab[i].extract;
             break;
         }
     }
     if (!s->extract)
         return AVERROR_BUG;

     return 0;
 }

 static int extract_extradata_filter(AVBSFContext *ctx, AVPacket *pkt)
 {
     ExtractExtradataContext *s = ctx->priv_data;
     uint8_t *extradata = NULL;
     int extradata_size;
     int ret = 0;

     ret = ff_bsf_get_packet_ref(ctx, pkt);
     if (ret < 0)
         return ret;

     ret = s->extract(ctx, pkt, &extradata, &extradata_size);
     if (ret < 0)
         goto fail;

     if (extradata) {
         ret = av_packet_add_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA,
                                       extradata, extradata_size);
         if (ret < 0) {
             av_freep(&extradata);
             goto fail;
         }
     }

     return 0;

 fail:
     av_packet_unref(pkt);
     return ret;
 }

 static void extract_extradata_close(AVBSFContext *ctx)
 {
     ExtractExtradataContext *s = ctx->priv_data;
     ff_av1_packet_uninit(&s->av1_pkt);
     ff_h2645_packet_uninit(&s->h2645_pkt);
 }

 static const enum AVCodecID codec_ids[] = {
     AV_CODEC_ID_AV1,
     AV_CODEC_ID_AVS2,
     AV_CODEC_ID_CAVS,
     AV_CODEC_ID_H264,
     AV_CODEC_ID_HEVC,
     AV_CODEC_ID_MPEG1VIDEO,
     AV_CODEC_ID_MPEG2VIDEO,
     AV_CODEC_ID_MPEG4,
     AV_CODEC_ID_VC1,
     AV_CODEC_ID_NONE,
 };

 #define OFFSET(x) offsetof(ExtractExtradataContext, x)
 #define FLAGS (AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_BSF_PARAM)
 static const AVOption options[] = {
     { "remove", "remove the extradata from the bitstream", OFFSET(remove), AV_OPT_TYPE_INT,
         { .i64 = 0 }, 0, 1, FLAGS },
     { NULL },
 };

 static const AVClass extract_extradata_class = {
     .class_name = "extract_extradata",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };

 const AVBitStreamFilter ff_extract_extradata_bsf = {
     .name           = "extract_extradata",
     .codec_ids      = codec_ids,
     .priv_data_size = sizeof(ExtractExtradataContext),
     .priv_class     = &extract_extradata_class,
     .init           = extract_extradata_init,
     .filter         = extract_extradata_filter,
     .close          = extract_extradata_close,
 };
	/*
	* 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 <stdint.h>

	#include "libavutil/common.h"
	#include "libavutil/intreadwrite.h"
	#include "libavutil/log.h"
	#include "libavutil/opt.h"

	#include "avcodec.h"
	#include "av1.h"
	#include "av1_parse.h"
	#include "bsf.h"
	#include "bytestream.h"
	#include "h2645_parse.h"
	#include "h264.h"
	#include "hevc.h"
	#include "vc1_common.h"

	typedef struct ExtractExtradataContext {
	const AVClass *class;

	int (extract)(AVBSFContext ctx, AVPacket *pkt,
	uint8_t *data, int size);

	/* AV1 specific fields */
	AV1Packet av1_pkt;

	/* H264/HEVC specific fields */
	H2645Packet h2645_pkt;

	/* AVOptions */
	int remove;
	} ExtractExtradataContext;

	static int val_in_array(const int *arr, int len, int val)
	{
	int i;
	for (i = 0; i < len; i++)
	if (arr[i] == val)
	return 1;
	return 0;
	}

	static int extract_extradata_av1(AVBSFContext ctx, AVPacket pkt,
	uint8_t *data, int size)
	{
	static const int extradata_obu_types[] = {
	AV1_OBU_SEQUENCE_HEADER, AV1_OBU_METADATA,
	};
	ExtractExtradataContext *s = ctx->priv_data;

	int extradata_size = 0, filtered_size = 0;
	int nb_extradata_obu_types = FF_ARRAY_ELEMS(extradata_obu_types);
	int i, has_seq = 0, ret = 0;

	ret = ff_av1_packet_split(&s->av1_pkt, pkt->data, pkt->size, ctx);
	if (ret < 0)
	return ret;

	for (i = 0; i < s->av1_pkt.nb_obus; i++) {
	AV1OBU *obu = &s->av1_pkt.obus[i];
	if (val_in_array(extradata_obu_types, nb_extradata_obu_types, obu->type)) {
	extradata_size += obu->raw_size;
	if (obu->type == AV1_OBU_SEQUENCE_HEADER)
	has_seq = 1;
	} else if (s->remove) {
	filtered_size += obu->raw_size;
	}
	}

	if (extradata_size && has_seq) {
	AVBufferRef *filtered_buf = NULL;
	PutByteContext pb_filtered_data, pb_extradata;
	uint8_t *extradata;

	if (s->remove) {
	filtered_buf = av_buffer_alloc(filtered_size + AV_INPUT_BUFFER_PADDING_SIZE);
	if (!filtered_buf) {
	return AVERROR(ENOMEM);
	}
	memset(filtered_buf->data + filtered_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
	}

	extradata = av_malloc(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
	if (!extradata) {
	av_buffer_unref(&filtered_buf);
	return AVERROR(ENOMEM);
	}
	memset(extradata + extradata_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);

	*data = extradata;
	*size = extradata_size;

	bytestream2_init_writer(&pb_extradata, extradata, extradata_size);
	if (s->remove)
	bytestream2_init_writer(&pb_filtered_data, filtered_buf->data, filtered_size);

	for (i = 0; i < s->av1_pkt.nb_obus; i++) {
	AV1OBU *obu = &s->av1_pkt.obus[i];
	if (val_in_array(extradata_obu_types, nb_extradata_obu_types,
	obu->type)) {
	bytestream2_put_bufferu(&pb_extradata, obu->raw_data, obu->raw_size);
	} else if (s->remove) {
	bytestream2_put_bufferu(&pb_filtered_data, obu->raw_data, obu->raw_size);
	}
	}

	if (s->remove) {
	av_buffer_unref(&pkt->buf);
	pkt->buf = filtered_buf;
	pkt->data = filtered_buf->data;
	pkt->size = filtered_size;
	}
	}

	return 0;
	}

	static int extract_extradata_h2645(AVBSFContext ctx, AVPacket pkt,
	uint8_t *data, int size)
	{
	static const int extradata_nal_types_hevc[] = {
	HEVC_NAL_VPS, HEVC_NAL_SPS, HEVC_NAL_PPS,
	};
	static const int extradata_nal_types_h264[] = {
	H264_NAL_SPS, H264_NAL_PPS,
	};

	ExtractExtradataContext *s = ctx->priv_data;

	int extradata_size = 0, filtered_size = 0;
	const int *extradata_nal_types;
	int nb_extradata_nal_types;
	int i, has_sps = 0, has_vps = 0, ret = 0;

	if (ctx->par_in->codec_id == AV_CODEC_ID_HEVC) {
	extradata_nal_types = extradata_nal_types_hevc;
	nb_extradata_nal_types = FF_ARRAY_ELEMS(extradata_nal_types_hevc);
	} else {
	extradata_nal_types = extradata_nal_types_h264;
	nb_extradata_nal_types = FF_ARRAY_ELEMS(extradata_nal_types_h264);
	}

	ret = ff_h2645_packet_split(&s->h2645_pkt, pkt->data, pkt->size,
	ctx, 0, 0, ctx->par_in->codec_id, 1, 0);
	if (ret < 0)
	return ret;

	for (i = 0; i < s->h2645_pkt.nb_nals; i++) {
	H2645NAL *nal = &s->h2645_pkt.nals[i];
	if (val_in_array(extradata_nal_types, nb_extradata_nal_types, nal->type)) {
	extradata_size += nal->raw_size + 3;
	if (ctx->par_in->codec_id == AV_CODEC_ID_HEVC) {
	if (nal->type == HEVC_NAL_SPS) has_sps = 1;
	if (nal->type == HEVC_NAL_VPS) has_vps = 1;
	} else {
	if (nal->type == H264_NAL_SPS) has_sps = 1;
	}
	} else if (s->remove) {
	filtered_size += nal->raw_size + 3;
	}
	}

	if (extradata_size &&
	((ctx->par_in->codec_id == AV_CODEC_ID_HEVC && has_sps && has_vps) \|\|
	(ctx->par_in->codec_id == AV_CODEC_ID_H264 && has_sps))) {
	AVBufferRef *filtered_buf = NULL;
	PutByteContext pb_filtered_data, pb_extradata;
	uint8_t *extradata;

	if (s->remove) {
	filtered_buf = av_buffer_alloc(filtered_size + AV_INPUT_BUFFER_PADDING_SIZE);
	if (!filtered_buf) {
	return AVERROR(ENOMEM);
	}
	memset(filtered_buf->data + filtered_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
	}

	extradata = av_malloc(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
	if (!extradata) {
	av_buffer_unref(&filtered_buf);
	return AVERROR(ENOMEM);
	}
	memset(extradata + extradata_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);

	*data = extradata;
	*size = extradata_size;

	bytestream2_init_writer(&pb_extradata, extradata, extradata_size);
	if (s->remove)
	bytestream2_init_writer(&pb_filtered_data, filtered_buf->data, filtered_size);

	for (i = 0; i < s->h2645_pkt.nb_nals; i++) {
	H2645NAL *nal = &s->h2645_pkt.nals[i];
	if (val_in_array(extradata_nal_types, nb_extradata_nal_types,
	nal->type)) {
	bytestream2_put_be24u(&pb_extradata, 1); //startcode
	bytestream2_put_bufferu(&pb_extradata, nal->raw_data, nal->raw_size);
	} else if (s->remove) {
	bytestream2_put_be24u(&pb_filtered_data, 1); // startcode
	bytestream2_put_bufferu(&pb_filtered_data, nal->raw_data, nal->raw_size);
	}
	}

	if (s->remove) {
	av_buffer_unref(&pkt->buf);
	pkt->buf = filtered_buf;
	pkt->data = filtered_buf->data;
	pkt->size = filtered_size;
	}
	}

	return 0;
	}

	static int extract_extradata_vc1(AVBSFContext ctx, AVPacket pkt,
	uint8_t *data, int size)
	{
	ExtractExtradataContext *s = ctx->priv_data;
	const uint8_t ptr = pkt->data, end = pkt->data + pkt->size;
	uint32_t state = UINT32_MAX;
	int has_extradata = 0, extradata_size = 0;

	while (ptr < end) {
	ptr = avpriv_find_start_code(ptr, end, &state);
	if (state == VC1_CODE_SEQHDR \|\| state == VC1_CODE_ENTRYPOINT) {
	has_extradata = 1;
	} else if (has_extradata && IS_MARKER(state)) {
	extradata_size = ptr - 4 - pkt->data;
	break;
	}
	}

	if (extradata_size) {
	*data = av_malloc(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
	if (!*data)
	return AVERROR(ENOMEM);

	memcpy(*data, pkt->data, extradata_size);
	memset(*data + extradata_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
	*size = extradata_size;

	if (s->remove) {
	pkt->data += extradata_size;
	pkt->size -= extradata_size;
	}
	}

	return 0;
	}

	static int extract_extradata_mpeg12(AVBSFContext ctx, AVPacket pkt,
	uint8_t *data, int size)
	{
	ExtractExtradataContext *s = ctx->priv_data;
	uint32_t state = UINT32_MAX;
	int i, found = 0;

	for (i = 0; i < pkt->size; i++) {
	state = (state << 8) \| pkt->data[i];
	if (state == 0x1B3)
	found = 1;
	else if (found && state != 0x1B5 && state < 0x200 && state >= 0x100) {
	if (i > 3) {
	*size = i - 3;
	data = av_malloc(size + AV_INPUT_BUFFER_PADDING_SIZE);
	if (!*data)
	return AVERROR(ENOMEM);

	memcpy(data, pkt->data, size);
	memset(data + size, 0, AV_INPUT_BUFFER_PADDING_SIZE);

	if (s->remove) {
	pkt->data += *size;
	pkt->size -= *size;
	}
	}
	break;
	}
	}
	return 0;
	}

	static int extract_extradata_mpeg4(AVBSFContext ctx, AVPacket pkt,
	uint8_t *data, int size)
	{
	ExtractExtradataContext *s = ctx->priv_data;
	const uint8_t ptr = pkt->data, end = pkt->data + pkt->size;
	uint32_t state = UINT32_MAX;

	while (ptr < end) {
	ptr = avpriv_find_start_code(ptr, end, &state);
	if (state == 0x1B3 \|\| state == 0x1B6) {
	if (ptr - pkt->data > 4) {
	*size = ptr - 4 - pkt->data;
	data = av_malloc(size + AV_INPUT_BUFFER_PADDING_SIZE);
	if (!*data)
	return AVERROR(ENOMEM);

	memcpy(data, pkt->data, size);
	memset(data + size, 0, AV_INPUT_BUFFER_PADDING_SIZE);

	if (s->remove) {
	pkt->data += *size;
	pkt->size -= *size;
	}
	}
	break;
	}
	}
	return 0;
	}

	static const struct {
	enum AVCodecID id;
	int (extract)(AVBSFContext ctx, AVPacket *pkt,
	uint8_t *data, int size);
	} extract_tab[] = {
	{ AV_CODEC_ID_AV1, extract_extradata_av1 },
	{ AV_CODEC_ID_AVS2, extract_extradata_mpeg4 },
	{ AV_CODEC_ID_CAVS, extract_extradata_mpeg4 },
	{ AV_CODEC_ID_H264, extract_extradata_h2645 },
	{ AV_CODEC_ID_HEVC, extract_extradata_h2645 },
	{ AV_CODEC_ID_MPEG1VIDEO, extract_extradata_mpeg12 },
	{ AV_CODEC_ID_MPEG2VIDEO, extract_extradata_mpeg12 },
	{ AV_CODEC_ID_MPEG4, extract_extradata_mpeg4 },
	{ AV_CODEC_ID_VC1, extract_extradata_vc1 },
	};

	static int extract_extradata_init(AVBSFContext *ctx)
	{
	ExtractExtradataContext *s = ctx->priv_data;
	int i;

	for (i = 0; i < FF_ARRAY_ELEMS(extract_tab); i++) {
	if (extract_tab[i].id == ctx->par_in->codec_id) {
	s->extract = extract_tab[i].extract;
	break;
	}
	}
	if (!s->extract)
	return AVERROR_BUG;

	return 0;
	}

	static int extract_extradata_filter(AVBSFContext ctx, AVPacket pkt)
	{
	ExtractExtradataContext *s = ctx->priv_data;
	uint8_t *extradata = NULL;
	int extradata_size;
	int ret = 0;

	ret = ff_bsf_get_packet_ref(ctx, pkt);
	if (ret < 0)
	return ret;

	ret = s->extract(ctx, pkt, &extradata, &extradata_size);
	if (ret < 0)
	goto fail;

	if (extradata) {
	ret = av_packet_add_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA,
	extradata, extradata_size);
	if (ret < 0) {
	av_freep(&extradata);
	goto fail;
	}
	}

	return 0;

	fail:
	av_packet_unref(pkt);
	return ret;
	}

	static void extract_extradata_close(AVBSFContext *ctx)
	{
	ExtractExtradataContext *s = ctx->priv_data;
	ff_av1_packet_uninit(&s->av1_pkt);
	ff_h2645_packet_uninit(&s->h2645_pkt);
	}

	static const enum AVCodecID codec_ids[] = {
	AV_CODEC_ID_AV1,
	AV_CODEC_ID_AVS2,
	AV_CODEC_ID_CAVS,
	AV_CODEC_ID_H264,
	AV_CODEC_ID_HEVC,
	AV_CODEC_ID_MPEG1VIDEO,
	AV_CODEC_ID_MPEG2VIDEO,
	AV_CODEC_ID_MPEG4,
	AV_CODEC_ID_VC1,
	AV_CODEC_ID_NONE,
	};

	#define OFFSET(x) offsetof(ExtractExtradataContext, x)
	#define FLAGS (AV_OPT_FLAG_VIDEO_PARAM\|AV_OPT_FLAG_BSF_PARAM)
	static const AVOption options[] = {
	{ "remove", "remove the extradata from the bitstream", OFFSET(remove), AV_OPT_TYPE_INT,
	{ .i64 = 0 }, 0, 1, FLAGS },
	{ NULL },
	};

	static const AVClass extract_extradata_class = {
	.class_name = "extract_extradata",
	.item_name = av_default_item_name,
	.option = options,
	.version = LIBAVUTIL_VERSION_INT,
	};

	const AVBitStreamFilter ff_extract_extradata_bsf = {
	.name = "extract_extradata",
	.codec_ids = codec_ids,
	.priv_data_size = sizeof(ExtractExtradataContext),
	.priv_class = &extract_extradata_class,
	.init = extract_extradata_init,
	.filter = extract_extradata_filter,
	.close = extract_extradata_close,
	};