/*

  * 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 <string.h>
 
 #include "libavutil/log.h"
 #include "libavutil/mem.h"
 #include "libavutil/opt.h"

 #include "libavutil/avstring.h"
 #include "libavutil/bprint.h"

 
 #include "avcodec.h"
 #include "bsf.h"
 
 struct AVBSFInternal {
     AVPacket *buffer_pkt;
     int eof;
 };
 
 void av_bsf_free(AVBSFContext **pctx)
 {
     AVBSFContext *ctx;
 
     if (!pctx || !*pctx)
         return;
     ctx = *pctx;
 
     if (ctx->filter->close)
         ctx->filter->close(ctx);
     if (ctx->filter->priv_class && ctx->priv_data)
         av_opt_free(ctx->priv_data);
 
     av_opt_free(ctx);
 
     av_packet_free(&ctx->internal->buffer_pkt);
     av_freep(&ctx->internal);
     av_freep(&ctx->priv_data);
 
     avcodec_parameters_free(&ctx->par_in);
     avcodec_parameters_free(&ctx->par_out);
 
     av_freep(pctx);
 }
 
 static void *bsf_child_next(void *obj, void *prev)
 {
     AVBSFContext *ctx = obj;
     if (!prev && ctx->filter->priv_class)
         return ctx->priv_data;
     return NULL;
 }
 
 static const AVClass bsf_class = {
     .class_name       = "AVBSFContext",
     .item_name        = av_default_item_name,
     .version          = LIBAVUTIL_VERSION_INT,
     .child_next       = bsf_child_next,
     .child_class_next = ff_bsf_child_class_next,
 };
 
 const AVClass *av_bsf_get_class(void)
 {
     return &bsf_class;
 }
 
 int av_bsf_alloc(const AVBitStreamFilter *filter, AVBSFContext **pctx)
 {
     AVBSFContext *ctx;
     int ret;
 
     ctx = av_mallocz(sizeof(*ctx));
     if (!ctx)
         return AVERROR(ENOMEM);
 
     ctx->av_class = &bsf_class;
     ctx->filter   = filter;
 
     ctx->par_in  = avcodec_parameters_alloc();
     ctx->par_out = avcodec_parameters_alloc();
     if (!ctx->par_in || !ctx->par_out) {
         ret = AVERROR(ENOMEM);
         goto fail;
     }
 
     ctx->internal = av_mallocz(sizeof(*ctx->internal));
     if (!ctx->internal) {
         ret = AVERROR(ENOMEM);
         goto fail;
     }
 
     ctx->internal->buffer_pkt = av_packet_alloc();
     if (!ctx->internal->buffer_pkt) {
         ret = AVERROR(ENOMEM);
         goto fail;
     }
 
     av_opt_set_defaults(ctx);
 
     /* allocate priv data and init private options */
     if (filter->priv_data_size) {
         ctx->priv_data = av_mallocz(filter->priv_data_size);
         if (!ctx->priv_data) {
             ret = AVERROR(ENOMEM);
             goto fail;
         }
         if (filter->priv_class) {
             *(const AVClass **)ctx->priv_data = filter->priv_class;
             av_opt_set_defaults(ctx->priv_data);
         }
     }
 
     *pctx = ctx;
     return 0;
 fail:
     av_bsf_free(&ctx);
     return ret;
 }
 
 int av_bsf_init(AVBSFContext *ctx)
 {
     int ret, i;
 
     /* check that the codec is supported */
     if (ctx->filter->codec_ids) {
         for (i = 0; ctx->filter->codec_ids[i] != AV_CODEC_ID_NONE; i++)
             if (ctx->par_in->codec_id == ctx->filter->codec_ids[i])
                 break;
         if (ctx->filter->codec_ids[i] == AV_CODEC_ID_NONE) {
             const AVCodecDescriptor *desc = avcodec_descriptor_get(ctx->par_in->codec_id);
             av_log(ctx, AV_LOG_ERROR, "Codec '%s' (%d) is not supported by the "
                    "bitstream filter '%s'. Supported codecs are: ",
                    desc ? desc->name : "unknown", ctx->par_in->codec_id, ctx->filter->name);
             for (i = 0; ctx->filter->codec_ids[i] != AV_CODEC_ID_NONE; i++) {
                 desc = avcodec_descriptor_get(ctx->filter->codec_ids[i]);
                 av_log(ctx, AV_LOG_ERROR, "%s (%d) ",
                        desc ? desc->name : "unknown", ctx->filter->codec_ids[i]);
             }
             av_log(ctx, AV_LOG_ERROR, "\n");
             return AVERROR(EINVAL);
         }
     }
 
     /* initialize output parameters to be the same as input
      * init below might overwrite that */
     ret = avcodec_parameters_copy(ctx->par_out, ctx->par_in);
     if (ret < 0)
         return ret;
 
     ctx->time_base_out = ctx->time_base_in;
 
     if (ctx->filter->init) {
         ret = ctx->filter->init(ctx);
         if (ret < 0)
             return ret;
     }
 
     return 0;
 }
 
 int av_bsf_send_packet(AVBSFContext *ctx, AVPacket *pkt)
 {

     if (!pkt || (!pkt->data && !pkt->side_data_elems)) {

         ctx->internal->eof = 1;
         return 0;
     }
 
     if (ctx->internal->eof) {
         av_log(ctx, AV_LOG_ERROR, "A non-NULL packet sent after an EOF.\n");
         return AVERROR(EINVAL);
     }
 
     if (ctx->internal->buffer_pkt->data ||
         ctx->internal->buffer_pkt->side_data_elems)
         return AVERROR(EAGAIN);
 
     av_packet_move_ref(ctx->internal->buffer_pkt, pkt);
 
     return 0;
 }
 
 int av_bsf_receive_packet(AVBSFContext *ctx, AVPacket *pkt)
 {
     return ctx->filter->filter(ctx, pkt);
 }
 
 int ff_bsf_get_packet(AVBSFContext *ctx, AVPacket **pkt)
 {
     AVBSFInternal *in = ctx->internal;
     AVPacket *tmp_pkt;
 
     if (in->eof)
         return AVERROR_EOF;
 
     if (!ctx->internal->buffer_pkt->data &&
         !ctx->internal->buffer_pkt->side_data_elems)
         return AVERROR(EAGAIN);
 
     tmp_pkt = av_packet_alloc();
     if (!tmp_pkt)
         return AVERROR(ENOMEM);
 
     *pkt = ctx->internal->buffer_pkt;
     ctx->internal->buffer_pkt = tmp_pkt;
 
     return 0;
 }

 
 int ff_bsf_get_packet_ref(AVBSFContext *ctx, AVPacket *pkt)
 {
     AVBSFInternal *in = ctx->internal;
 
     if (in->eof)
         return AVERROR_EOF;
 
     if (!ctx->internal->buffer_pkt->data &&
         !ctx->internal->buffer_pkt->side_data_elems)
         return AVERROR(EAGAIN);
 
     av_packet_move_ref(pkt, ctx->internal->buffer_pkt);
 
     return 0;
 }

 
 typedef struct BSFListContext {
     const AVClass *class;
 
     AVBSFContext **bsfs;
     int nb_bsfs;
 
     unsigned idx;           // index of currently processed BSF
     unsigned flushed_idx;   // index of BSF being flushed
 

     char * item_name;

 } BSFListContext;
 
 
 static int bsf_list_init(AVBSFContext *bsf)
 {
     BSFListContext *lst = bsf->priv_data;
     int ret, i;
     const AVCodecParameters *cod_par = bsf->par_in;
     AVRational tb = bsf->time_base_in;
 
     for (i = 0; i < lst->nb_bsfs; ++i) {
         ret = avcodec_parameters_copy(lst->bsfs[i]->par_in, cod_par);
         if (ret < 0)
             goto fail;
 
         lst->bsfs[i]->time_base_in = tb;
 
         ret = av_bsf_init(lst->bsfs[i]);
         if (ret < 0)
             goto fail;
 
         cod_par = lst->bsfs[i]->par_out;
         tb = lst->bsfs[i]->time_base_out;
     }
 
     bsf->time_base_out = tb;
     ret = avcodec_parameters_copy(bsf->par_out, cod_par);
 
 fail:
     return ret;
 }
 
 static int bsf_list_filter(AVBSFContext *bsf, AVPacket *out)
 {
     BSFListContext *lst = bsf->priv_data;
     int ret;
 
     if (!lst->nb_bsfs)
         return ff_bsf_get_packet_ref(bsf, out);
 
     while (1) {
         if (lst->idx > lst->flushed_idx) {
             ret = av_bsf_receive_packet(lst->bsfs[lst->idx-1], out);
             if (ret == AVERROR(EAGAIN)) {
                 /* no more packets from idx-1, try with previous */
                 ret = 0;
                 lst->idx--;
                 continue;
             } else if (ret == AVERROR_EOF) {
                 /* filter idx-1 is done, continue with idx...nb_bsfs */
                 lst->flushed_idx = lst->idx;
                 continue;
             }else if (ret < 0) {
                 /* filtering error */
                 break;
             }
         } else {
             ret = ff_bsf_get_packet_ref(bsf, out);
             if (ret == AVERROR_EOF) {
                 lst->idx = lst->flushed_idx;
             } else if (ret < 0)
                 break;
         }
 
         if (lst->idx < lst->nb_bsfs) {
             AVPacket *pkt;
             if (ret == AVERROR_EOF && lst->idx == lst->flushed_idx) {
                 /* ff_bsf_get_packet_ref returned EOF and idx is first
                  * filter of yet not flushed filter chain */
                 pkt = NULL;
             } else {
                 pkt = out;
             }
             ret = av_bsf_send_packet(lst->bsfs[lst->idx], pkt);
             if (ret < 0)
                 break;
             lst->idx++;
         } else {
             /* The end of filter chain, break to return result */
             break;
         }
     }
 
     if (ret < 0)
         av_packet_unref(out);
 
     return ret;
 }
 
 static void bsf_list_close(AVBSFContext *bsf)
 {
     BSFListContext *lst = bsf->priv_data;
     int i;
 
     for (i = 0; i < lst->nb_bsfs; ++i)
         av_bsf_free(&lst->bsfs[i]);
     av_freep(&lst->bsfs);

     av_freep(&lst->item_name);
 }
 
 static const char *bsf_list_item_name(void *ctx)
 {
     static const char *null_filter_name = "null";
     AVBSFContext *bsf_ctx = ctx;
     BSFListContext *lst = bsf_ctx->priv_data;
 
     if (!lst->nb_bsfs)
         return null_filter_name;
 
     if (!lst->item_name) {
         int i;
         AVBPrint bp;
         av_bprint_init(&bp, 16, 128);
 
         av_bprintf(&bp, "bsf_list(");
         for (i = 0; i < lst->nb_bsfs; i++)
             av_bprintf(&bp, i ? ",%s" : "%s", lst->bsfs[i]->filter->name);
         av_bprintf(&bp, ")");
 
         av_bprint_finalize(&bp, &lst->item_name);
     }
 
     return lst->item_name;

 }
 
 static const AVClass bsf_list_class = {
         .class_name = "bsf_list",

         .item_name  = bsf_list_item_name,

         .version    = LIBAVUTIL_VERSION_INT,
 };
 
 const AVBitStreamFilter ff_list_bsf = {
         .name           = "bsf_list",
         .priv_data_size = sizeof(BSFListContext),
         .priv_class     = &bsf_list_class,
         .init           = bsf_list_init,
         .filter         = bsf_list_filter,
         .close          = bsf_list_close,
 };
 
 struct AVBSFList {
     AVBSFContext **bsfs;
     int nb_bsfs;
 };
 
 AVBSFList *av_bsf_list_alloc(void)
 {
     return av_mallocz(sizeof(AVBSFList));
 }
 
 void av_bsf_list_free(AVBSFList **lst)
 {
     int i;
 

     if (!*lst)

         return;
 
     for (i = 0; i < (*lst)->nb_bsfs; ++i)
         av_bsf_free(&(*lst)->bsfs[i]);
     av_free((*lst)->bsfs);
     av_freep(lst);
 }
 
 int av_bsf_list_append(AVBSFList *lst, AVBSFContext *bsf)
 {
     return av_dynarray_add_nofree(&lst->bsfs, &lst->nb_bsfs, bsf);
 }
 
 int av_bsf_list_append2(AVBSFList *lst, const char *bsf_name, AVDictionary ** options)
 {
     int ret;
     const AVBitStreamFilter *filter;
     AVBSFContext *bsf;
 
     filter = av_bsf_get_by_name(bsf_name);
     if (!filter)
         return AVERROR_BSF_NOT_FOUND;
 
     ret = av_bsf_alloc(filter, &bsf);
     if (ret < 0)
         return ret;
 
     if (options) {

         ret = av_opt_set_dict2(bsf, options, AV_OPT_SEARCH_CHILDREN);

         if (ret < 0)
             goto end;
     }
 
     ret = av_bsf_list_append(lst, bsf);
 
 end:
     if (ret < 0)
         av_bsf_free(&bsf);
 
     return ret;
 }
 
 int av_bsf_list_finalize(AVBSFList **lst, AVBSFContext **bsf)
 {
     int ret = 0;
     BSFListContext *ctx;
 
     if ((*lst)->nb_bsfs == 1) {
         *bsf = (*lst)->bsfs[0];
         av_freep(&(*lst)->bsfs);
         (*lst)->nb_bsfs = 0;
         goto end;
     }
 
     ret = av_bsf_alloc(&ff_list_bsf, bsf);
     if (ret < 0)
         return ret;
 
     ctx = (*bsf)->priv_data;
 
     ctx->bsfs = (*lst)->bsfs;
     ctx->nb_bsfs = (*lst)->nb_bsfs;
 
 end:
     av_freep(lst);
     return ret;
 }
 
 static int bsf_parse_single(const char *str, AVBSFList *bsf_lst)
 {
     char *bsf_name, *bsf_options_str, *buf;
     AVDictionary *bsf_options = NULL;
     int ret = 0;
 
     if (!(buf = av_strdup(str)))
         return AVERROR(ENOMEM);
 
     bsf_name = av_strtok(buf, "=", &bsf_options_str);
     if (!bsf_name) {
         ret = AVERROR(EINVAL);
         goto end;
     }
 
     if (bsf_options_str) {
         ret = av_dict_parse_string(&bsf_options, bsf_options_str, "=", ":", 0);
         if (ret < 0)
             goto end;
     }
 
     ret = av_bsf_list_append2(bsf_lst, bsf_name, &bsf_options);
 
     av_dict_free(&bsf_options);
 end:
     av_free(buf);
     return ret;
 }
 
 int av_bsf_list_parse_str(const char *str, AVBSFContext **bsf_lst)
 {
     AVBSFList *lst;
     char *bsf_str, *buf, *dup, *saveptr;
     int ret;
 
     if (!str)
         return av_bsf_get_null_filter(bsf_lst);
 
     lst = av_bsf_list_alloc();
     if (!lst)
         return AVERROR(ENOMEM);
 

     if (!(dup = buf = av_strdup(str))) {
         ret = AVERROR(ENOMEM);
         goto end;
     }

 
     while (1) {
         bsf_str = av_strtok(buf, ",", &saveptr);
         if (!bsf_str)
             break;
 
         ret = bsf_parse_single(bsf_str, lst);
         if (ret < 0)
             goto end;
 
         buf = NULL;
     }
 
     ret = av_bsf_list_finalize(&lst, bsf_lst);
 end:
     if (ret < 0)
         av_bsf_list_free(&lst);
     av_free(dup);
     return ret;
 }
 
 int av_bsf_get_null_filter(AVBSFContext **bsf)
 {
     return av_bsf_alloc(&ff_list_bsf, bsf);
 }