/*

 * This file is part of mpv.

 *

 * mpv 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.

 *

 * mpv 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 mpv.  If not, see <http://www.gnu.org/licenses/>.

 */

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <assert.h>

#include <libavcodec/avcodec.h>

#include <libavutil/hdr_dynamic_metadata.h>

#include <libavutil/imgutils.h>

#include <libavutil/intreadwrite.h>

#include "common/av_common.h"

#include "common/common.h"

#include "demux.h"

#include "demux/ebml.h"

#include "packet_pool.h"

#include "packet.h"

// Free any refcounted data dp holds (but don't free dp itself). This does not

// care about pointers that are _not_ refcounted (like demux_packet.codec).

// Normally, a user should use talloc_free(dp). This function is only for

// annoyingly specific obscure use cases.

void demux_packet_unref_contents(struct demux_packet *dp)

{

    if (dp->avpacket) {

        mp_assert(!dp->is_cached);

        av_packet_free(&dp->avpacket);

        dp->buffer = NULL;

        dp->len = 0;

        dp->is_wrapped_avframe = false;

    }

}

static void packet_destroy(void *ptr)

{

    struct demux_packet *dp = ptr;

    demux_packet_unref_contents(dp);

}

static void set_packet_defaults(struct demux_packet *dp)

{

    *dp = (struct demux_packet) {

        .pts = MP_NOPTS_VALUE,

        .dts = MP_NOPTS_VALUE,

        .duration = -1,

        .pos = -1,

        .start = MP_NOPTS_VALUE,

        .end = MP_NOPTS_VALUE,

        .stream = -1,

        .animated = -1,

    };

}

// This frees a packet backing allocations, but does not free dp itself, or

// AVPacket inside dp, which is restored to default state.

void demux_packet_unref(struct demux_packet *dp)

{

    if (!dp)

        return;

    struct AVPacket *avpkt = dp ? dp->avpacket : NULL;

    if (avpkt)

        av_packet_unref(avpkt);

    ta_free_children(dp);

    set_packet_defaults(dp);

    dp->avpacket = avpkt;

}

static struct demux_packet *packet_create(struct demux_packet_pool *pool)

{

    struct demux_packet *dp = pool ? demux_packet_pool_pop(pool) : NULL;

    if (!dp) {

        dp = talloc(NULL, struct demux_packet);

        talloc_set_destructor(dp, packet_destroy);

        set_packet_defaults(dp);

    }

    if (!dp->avpacket)

        dp->avpacket = av_packet_alloc();

    MP_HANDLE_OOM(dp->avpacket);

    return dp;

}

// This actually preserves only data and side data, not PTS/DTS/pos/etc.

// It also allows avpkt->data==NULL with avpkt->size!=0 - the libavcodec API

// does not allow it, but we do it to simplify new_demux_packet().

struct demux_packet *new_demux_packet_from_avpacket(struct demux_packet_pool *pool,

                                                    struct AVPacket *avpkt)

{

    if (avpkt->size > 1000000000)

        return NULL;

    struct demux_packet *dp = packet_create(pool);

    int r = -1;

    if (avpkt->data) {

        // We hope that this function won't need/access AVPacket input padding,

        // because otherwise new_demux_packet_from() wouldn't work.

        r = av_packet_ref(dp->avpacket, avpkt);

    } else {

        r = av_new_packet(dp->avpacket, avpkt->size);

    }

    if (r < 0) {

        talloc_free(dp);

        return NULL;

    }

    dp->buffer = dp->avpacket->data;

    dp->len = dp->avpacket->size;

    return dp;

}

// (buf must include proper padding)

struct demux_packet *new_demux_packet_from_buf(struct demux_packet_pool *pool,

                                               struct AVBufferRef *buf)

{

    if (!buf)

        return NULL;

    if (buf->size > 1000000000)

        return NULL;

    struct demux_packet *dp = packet_create(pool);

    dp->avpacket->buf = av_buffer_ref(buf);

    if (!dp->avpacket->buf) {

        talloc_free(dp);

        return NULL;

    }

    dp->avpacket->data = dp->buffer = buf->data;

    dp->avpacket->size = dp->len = buf->size;

    return dp;

}

// Input data doesn't need to be padded.

struct demux_packet *new_demux_packet_from(struct demux_packet_pool *pool, void *data, size_t len)

{

    struct demux_packet *dp = new_demux_packet(pool, len);

    if (!dp)

        return NULL;

    memcpy(dp->avpacket->data, data, len);

    return dp;

}

struct demux_packet *new_demux_packet(struct demux_packet_pool *pool, size_t len)

{

    if (len > INT_MAX)

        return NULL;

    struct demux_packet *dp = packet_create(pool);

    int r = av_new_packet(dp->avpacket, len);

    if (r < 0) {

        talloc_free(dp);

        return NULL;

    }

    dp->buffer = dp->avpacket->data;

    dp->len = len;

    return dp;

}

void demux_packet_shorten(struct demux_packet *dp, size_t len)

{

    mp_assert(len <= dp->len);

    if (dp->len) {

        dp->len = len;

        memset(dp->buffer + dp->len, 0, AV_INPUT_BUFFER_PADDING_SIZE);

    }

}

void free_demux_packet(struct demux_packet *dp)

{

    talloc_free(dp);

}

void demux_packet_copy_attribs(struct demux_packet *dst, struct demux_packet *src)

{

    dst->pts = src->pts;

    dst->dts = src->dts;

    dst->duration = src->duration;

    dst->pos = src->pos;

    dst->is_wrapped_avframe = src->is_wrapped_avframe;

    dst->segmented = src->segmented;

    dst->start = src->start;

    dst->end = src->end;

    dst->codec = src->codec;

    dst->back_restart = src->back_restart;

    dst->back_preroll = src->back_preroll;

    dst->keyframe = src->keyframe;

    dst->stream = src->stream;

}

struct demux_packet *demux_copy_packet(struct demux_packet_pool *pool, struct demux_packet *dp)

{

    struct demux_packet *new = NULL;

    if (dp->avpacket) {

        new = new_demux_packet_from_avpacket(pool, dp->avpacket);

    } else {

        // Some packets might be not created by new_demux_packet*().

        new = new_demux_packet_from(pool, dp->buffer, dp->len);

    }

    if (!new)

        return NULL;

    demux_packet_copy_attribs(new, dp);

    return new;

}

#define ROUND_ALLOC(s) MP_ALIGN_UP((s), 16)

// Attempt to estimate the total memory consumption of the given packet.

// This is important if we store thousands of packets and not to exceed

// user-provided limits. Of course we can't know how much memory internal

// fragmentation of the libc memory allocator will waste.

// Note that this should return a "stable" value - e.g. if a new packet ref

// is created, this should return the same value with the new ref. (This

// implies the value is not exact and does not return the actual size of

// memory wasted due to internal fragmentation.)

size_t demux_packet_estimate_total_size(struct demux_packet *dp)

{

    size_t size = ROUND_ALLOC(sizeof(struct demux_packet));

    size += 8 * sizeof(void *); // ta  overhead

    size += 10 * sizeof(void *); // additional estimate for ta_ext_header

    if (dp->avpacket) {

        mp_assert(!dp->is_cached);

        size += ROUND_ALLOC(dp->len);

        if (dp->is_wrapped_avframe) {

            mp_require(dp->buffer);

            const AVFrame *frame = (AVFrame *)dp->buffer;

            if (frame->hw_frames_ctx) {

                const AVHWFramesContext *hwctx = (AVHWFramesContext *)frame->hw_frames_ctx->data;

                int r = av_image_get_buffer_size(hwctx->sw_format, hwctx->width, hwctx->height, 16);

                mp_require(r >= 0);

                size += ROUND_ALLOC(r);

            }

            for (int i = 0; i < MP_ARRAY_SIZE(frame->buf) && frame->buf[i]; ++i)

                size += ROUND_ALLOC(frame->buf[i]->size);

            size += ROUND_ALLOC(frame->nb_extended_buf * sizeof(frame->extended_buf[0]));

            for (int i = 0; i < frame->nb_extended_buf; ++i) {

                size += ROUND_ALLOC(sizeof(*frame->extended_buf[i]));

                size += ROUND_ALLOC(frame->extended_buf[i]->size);

            }

            size += ROUND_ALLOC(frame->nb_side_data * sizeof(frame->side_data[0]));

            for (int i = 0; i < frame->nb_side_data; ++i) {

                size += ROUND_ALLOC(sizeof(*frame->side_data[i]));

                size += ROUND_ALLOC(frame->side_data[i]->size);

            }

        }

        size += ROUND_ALLOC(sizeof(AVPacket));

        size += 8 * sizeof(void *); // ta  overhead

        size += ROUND_ALLOC(sizeof(AVBufferRef));

        size += ROUND_ALLOC(64); // upper bound estimate on sizeof(AVBuffer)

        size += ROUND_ALLOC(dp->avpacket->side_data_elems *

                            sizeof(dp->avpacket->side_data[0]));

        for (int n = 0; n < dp->avpacket->side_data_elems; n++)

            size += ROUND_ALLOC(dp->avpacket->side_data[n].size);

    }

    return size;

}

int demux_packet_set_padding(struct demux_packet *dp, int start, int end)

{

    if (!start && !end)

        return 0;

    if (!dp->avpacket)

        return -1;

    uint8_t *p = av_packet_new_side_data(dp->avpacket, AV_PKT_DATA_SKIP_SAMPLES, 10);

    if (!p)

        return -1;

    AV_WL32(p + 0, start);

    AV_WL32(p + 4, end);

    return 0;

}

int demux_packet_add_blockadditional(struct demux_packet *dp, uint64_t id,

                                     void *data, size_t size)

{

    if (!dp->avpacket)

        return -1;

    switch (id) {

    case MATROSKA_BLOCK_ADD_ID_TYPE_ITU_T_T35: {

        static const uint8_t ITU_T_T35_COUNTRY_CODE_US = 0xB5;

        static const uint16_t ITU_T_T35_PROVIDER_CODE_SMTPE = 0x3C;

        if (size < 6)

            break;

        uint8_t *p = data;

        uint8_t country_code = AV_RB8(p);

        p += sizeof(country_code);

        uint16_t provider_code = AV_RB16(p);

        p += sizeof(provider_code);

        if (country_code != ITU_T_T35_COUNTRY_CODE_US ||

            provider_code != ITU_T_T35_PROVIDER_CODE_SMTPE)

            break;

        uint16_t provider_oriented_code = AV_RB16(p);

        p += sizeof(provider_oriented_code);

        uint8_t application_identifier = AV_RB8(p);

        p += sizeof(application_identifier);

        if (provider_oriented_code != 1 || application_identifier != 4)

            break;

        size_t hdrplus_size;

        AVDynamicHDRPlus *hdrplus = av_dynamic_hdr_plus_alloc(&hdrplus_size);

        MP_HANDLE_OOM(hdrplus);

        if (av_dynamic_hdr_plus_from_t35(hdrplus, p, size - (p - (uint8_t *)data)) < 0 ||

            av_packet_add_side_data(dp->avpacket, AV_PKT_DATA_DYNAMIC_HDR10_PLUS,

                                    (uint8_t *)hdrplus, hdrplus_size) < 0)

        {

            av_free(hdrplus);

            return -1;

        }

        return 0;

    }

    default:

        break;

    }

    uint8_t *sd = av_packet_new_side_data(dp->avpacket,

                                          AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL,

                                          8 + size);

    if (!sd)

        return -1;

    AV_WB64(sd, id);

    if (size > 0)

        memcpy(sd + 8, data, size);

    return 0;

}