/*

 * 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 "config_components.h"

#include "libavutil/avassert.h"

#include "libavutil/log.h"

#include "libavutil/mem.h"

#include "libavutil/opt.h"

#include "libavutil/avstring.h"

#include "libavutil/bprint.h"

#include "bsf.h"

#include "bsf_internal.h"

#include "codec_desc.h"

#include "codec_par.h"

#include "packet_internal.h"

static av_always_inline const FFBitStreamFilter *ff_bsf(const AVBitStreamFilter *bsf)

{

    return (const FFBitStreamFilter*)bsf;

}

typedef struct FFBSFContext {

    AVBSFContext pub;

    AVPacket *buffer_pkt;

    int eof;

} FFBSFContext;

static av_always_inline FFBSFContext *ffbsfcontext(AVBSFContext *ctx)

{

    return (FFBSFContext *)ctx;

}

void av_bsf_free(AVBSFContext **pctx)

{

    AVBSFContext *ctx;

    FFBSFContext *bsfi;

    if (!pctx || !*pctx)

        return;

    ctx  = *pctx;

    bsfi = ffbsfcontext(ctx);

    if (ctx->priv_data) {

        if (ff_bsf(ctx->filter)->close)

            ff_bsf(ctx->filter)->close(ctx);

        if (ctx->filter->priv_class)

            av_opt_free(ctx->priv_data);

        av_freep(&ctx->priv_data);

    }

    av_packet_free(&bsfi->buffer_pkt);

    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 char *bsf_to_name(void *bsf)

{

    return ((AVBSFContext *)bsf)->filter->name;

}

static const AVClass bsf_class = {

    .class_name       = "AVBSFContext",

    .item_name        = bsf_to_name,

    .version          = LIBAVUTIL_VERSION_INT,

    .child_next       = bsf_child_next,

    .child_class_iterate = ff_bsf_child_class_iterate,

    .category         = AV_CLASS_CATEGORY_BITSTREAM_FILTER,

};

const AVClass *av_bsf_get_class(void)

{

    return &bsf_class;

}

int av_bsf_alloc(const AVBitStreamFilter *filter, AVBSFContext **pctx)

{

    AVBSFContext *ctx;

    FFBSFContext *bsfi;

    int ret;

    bsfi = av_mallocz(sizeof(*bsfi));

    if (!bsfi)

        return AVERROR(ENOMEM);

    ctx  = &bsfi->pub;

    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;

    }

    /* allocate priv data and init private options */

    if (ff_bsf(filter)->priv_data_size) {

        ctx->priv_data = av_mallocz(ff_bsf(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);

        }

    }

    bsfi->buffer_pkt = av_packet_alloc();

    if (!bsfi->buffer_pkt) {

        ret = AVERROR(ENOMEM);

        goto fail;

    }

    *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++) {

                enum AVCodecID codec_id = ctx->filter->codec_ids[i];

                av_log(ctx, AV_LOG_ERROR, "%s (%d) ",

                       avcodec_get_name(codec_id), codec_id);

            }

            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 (ff_bsf(ctx->filter)->init) {

        ret = ff_bsf(ctx->filter)->init(ctx);

        if (ret < 0)

            return ret;

    }

    return 0;

}

void av_bsf_flush(AVBSFContext *ctx)

{

    FFBSFContext *const bsfi = ffbsfcontext(ctx);

    bsfi->eof = 0;

    av_packet_unref(bsfi->buffer_pkt);

    if (ff_bsf(ctx->filter)->flush)

        ff_bsf(ctx->filter)->flush(ctx);

}

int av_bsf_send_packet(AVBSFContext *ctx, AVPacket *pkt)

{

    FFBSFContext *const bsfi = ffbsfcontext(ctx);

    int ret;

    if (!pkt || AVPACKET_IS_EMPTY(pkt)) {

        if (pkt)

            av_packet_unref(pkt);

        bsfi->eof = 1;

        return 0;

    }

    if (bsfi->eof) {

        av_log(ctx, AV_LOG_ERROR, "A non-NULL packet sent after an EOF.\n");

        return AVERROR(EINVAL);

    }

    if (!AVPACKET_IS_EMPTY(bsfi->buffer_pkt))

        return AVERROR(EAGAIN);

    ret = av_packet_make_refcounted(pkt);

    if (ret < 0)

        return ret;

    av_packet_move_ref(bsfi->buffer_pkt, pkt);

    return 0;

}

int av_bsf_receive_packet(AVBSFContext *ctx, AVPacket *pkt)

{

    return ff_bsf(ctx->filter)->filter(ctx, pkt);

}

int ff_bsf_get_packet(AVBSFContext *ctx, AVPacket **pkt)

{

    FFBSFContext *const bsfi = ffbsfcontext(ctx);

    AVPacket *tmp_pkt;

    if (bsfi->eof)

        return AVERROR_EOF;

    if (AVPACKET_IS_EMPTY(bsfi->buffer_pkt))

        return AVERROR(EAGAIN);

    tmp_pkt = av_packet_alloc();

    if (!tmp_pkt)

        return AVERROR(ENOMEM);

    *pkt = bsfi->buffer_pkt;

    bsfi->buffer_pkt = tmp_pkt;

    return 0;

}

int ff_bsf_get_packet_ref(AVBSFContext *ctx, AVPacket *pkt)

{

    FFBSFContext *const bsfi = ffbsfcontext(ctx);

    if (bsfi->eof)

        return AVERROR_EOF;

    if (AVPACKET_IS_EMPTY(bsfi->buffer_pkt))

        return AVERROR(EAGAIN);

    av_packet_move_ref(pkt, bsfi->buffer_pkt);

    return 0;

}

typedef struct BSFListContext {

    const AVClass *class;

    AVBSFContext **bsfs;

    int nb_bsfs;

    unsigned idx;           // index of currently processed BSF

    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, eof = 0;

    if (!lst->nb_bsfs)

        return ff_bsf_get_packet_ref(bsf, out);

    while (1) {

        /* get a packet from the previous filter up the chain */

        if (lst->idx)

            ret = av_bsf_receive_packet(lst->bsfs[lst->idx-1], out);

        else

            ret = ff_bsf_get_packet_ref(bsf, out);

        if (ret == AVERROR(EAGAIN)) {

            if (!lst->idx)

                return ret;

            lst->idx--;

            continue;

        } else if (ret == AVERROR_EOF) {

            eof = 1;

        } else if (ret < 0)

            return ret;

        /* send it to the next filter down the chain */

        if (lst->idx < lst->nb_bsfs) {

            ret = av_bsf_send_packet(lst->bsfs[lst->idx], eof ? NULL : out);

            av_assert1(ret != AVERROR(EAGAIN));

            if (ret < 0) {

                av_packet_unref(out);

                return ret;

            }

            lst->idx++;

            eof = 0;

        } else if (eof) {

            return ret;

        } else {

            return 0;

        }

    }

}

static void bsf_list_flush(AVBSFContext *bsf)

{

    BSFListContext *lst = bsf->priv_data;

    for (int i = 0; i < lst->nb_bsfs; i++)

        av_bsf_flush(lst->bsfs[i]);

    lst->idx = 0;

}

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,

};

static const FFBitStreamFilter list_bsf = {

        .p.name         = "bsf_list",

        .p.priv_class   = &bsf_list_class,

        .priv_data_size = sizeof(BSFListContext),

        .init           = bsf_list_init,

        .filter         = bsf_list_filter,

        .flush          = bsf_list_flush,

        .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);

}

static int bsf_list_append_internal(AVBSFList *lst, const char *bsf_name, const char *options, AVDictionary ** options_dict)

{

    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 && filter->priv_class) {

        const AVOption *opt = av_opt_next(bsf->priv_data, NULL);

        const char * shorthand[2] = {NULL};

        if (opt)

            shorthand[0] = opt->name;

        ret = av_opt_set_from_string(bsf->priv_data, options, shorthand, "=", ":");

        if (ret < 0)

            goto end;

    }

    if (options_dict) {

        ret = av_opt_set_dict2(bsf, options_dict, 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_append2(AVBSFList *lst, const char *bsf_name, AVDictionary ** options)

{

    return bsf_list_append_internal(lst, bsf_name, NULL, options);

}

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(&list_bsf.p, 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(char *str, AVBSFList *bsf_lst)

{

    char *bsf_name, *bsf_options_str;

    bsf_name = av_strtok(str, "=", &bsf_options_str);

    if (!bsf_name)

        return AVERROR(EINVAL);

    return bsf_list_append_internal(bsf_lst, bsf_name, bsf_options_str, NULL);

}

int av_bsf_list_parse_str(const char *str, AVBSFContext **bsf_lst)

{

    AVBSFList *lst;

    int ret;

    if (!str)

        return av_bsf_get_null_filter(bsf_lst);

    lst = av_bsf_list_alloc();

    if (!lst)

        return AVERROR(ENOMEM);

    do {

        char *bsf_str = av_get_token(&str, ",");

        ret = bsf_parse_single(bsf_str, lst);

        av_free(bsf_str);

        if (ret < 0)

            goto end;

    } while (*str && *++str);

    ret = av_bsf_list_finalize(&lst, bsf_lst);

end:

    if (ret < 0)

        av_bsf_list_free(&lst);

    return ret;

}

int av_bsf_get_null_filter(AVBSFContext **bsf)

{

#if CONFIG_NULL_BSF

    extern const FFBitStreamFilter ff_null_bsf;

    return av_bsf_alloc(&ff_null_bsf.p, bsf);

#else

    return av_bsf_alloc(&list_bsf.p, bsf);

#endif

}