movenc.c

/*
 * MOV, 3GP, MP4 muxer
 * Copyright (c) 2003 Thomas Raivio
 * Copyright (c) 2004 Gildas Bazin <gbazin at videolan dot org>
 * Copyright (c) 2009 Baptiste Coudurier <baptiste dot coudurier at gmail dot com>
 *
 * 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 <inttypes.h>

#include "movenc.h"
#include "avformat.h"
#include "avio_internal.h"
#include "riff.h"
#include "avio.h"
#include "isom.h"
#include "avc.h"
#include "libavcodec/ac3_parser.h"
#include "libavcodec/get_bits.h"
#include "libavcodec/put_bits.h"
#include "libavcodec/vc1_common.h"
#include "libavcodec/raw.h"
#include "internal.h"
#include "libavutil/avstring.h"
#include "libavutil/intfloat.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
#include "libavutil/dict.h"
#include "libavutil/pixdesc.h"
#include "libavutil/timecode.h"
#include "hevc.h"
#include "rtpenc.h"
#include "mov_chan.h"

#undef NDEBUG
#include <assert.h>

static const AVOption options[] = {
    { "movflags", "MOV muxer flags", offsetof(MOVMuxContext, flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "movflags" },
    { "rtphint", "Add RTP hint tracks", 0, AV_OPT_TYPE_CONST, {.i64 = FF_MOV_FLAG_RTP_HINT}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "movflags" },
    { "moov_size", "maximum moov size so it can be placed at the begin", offsetof(MOVMuxContext, reserved_moov_size), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, 0 },
    { "empty_moov", "Make the initial moov atom empty", 0, AV_OPT_TYPE_CONST, {.i64 = FF_MOV_FLAG_EMPTY_MOOV}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "movflags" },
    { "frag_keyframe", "Fragment at video keyframes", 0, AV_OPT_TYPE_CONST, {.i64 = FF_MOV_FLAG_FRAG_KEYFRAME}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "movflags" },
    { "separate_moof", "Write separate moof/mdat atoms for each track", 0, AV_OPT_TYPE_CONST, {.i64 = FF_MOV_FLAG_SEPARATE_MOOF}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "movflags" },
    { "frag_custom", "Flush fragments on caller requests", 0, AV_OPT_TYPE_CONST, {.i64 = FF_MOV_FLAG_FRAG_CUSTOM}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "movflags" },
    { "isml", "Create a live smooth streaming feed (for pushing to a publishing point)", 0, AV_OPT_TYPE_CONST, {.i64 = FF_MOV_FLAG_ISML}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "movflags" },
    { "faststart", "Run a second pass to put the index (moov atom) at the beginning of the file", 0, AV_OPT_TYPE_CONST, {.i64 = FF_MOV_FLAG_FASTSTART}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "movflags" },
    { "omit_tfhd_offset", "Omit the base data offset in tfhd atoms", 0, AV_OPT_TYPE_CONST, {.i64 = FF_MOV_FLAG_OMIT_TFHD_OFFSET}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "movflags" },
    { "disable_chpl", "Disable Nero chapter atom", 0, AV_OPT_TYPE_CONST, {.i64 = FF_MOV_FLAG_DISABLE_CHPL}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "movflags" },
    { "default_base_moof", "Set the default-base-is-moof flag in tfhd atoms", 0, AV_OPT_TYPE_CONST, {.i64 = FF_MOV_FLAG_DEFAULT_BASE_MOOF}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "movflags" },
    { "dash", "Write DASH compatible fragmented MP4", 0, AV_OPT_TYPE_CONST, {.i64 = FF_MOV_FLAG_DASH}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "movflags" },
    { "frag_discont", "Signal that the next fragment is discontinuous from earlier ones", 0, AV_OPT_TYPE_CONST, {.i64 = FF_MOV_FLAG_FRAG_DISCONT}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "movflags" },
    FF_RTP_FLAG_OPTS(MOVMuxContext, rtp_flags),
    { "skip_iods", "Skip writing iods atom.", offsetof(MOVMuxContext, iods_skip), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
    { "iods_audio_profile", "iods audio profile atom.", offsetof(MOVMuxContext, iods_audio_profile), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 255, AV_OPT_FLAG_ENCODING_PARAM},
    { "iods_video_profile", "iods video profile atom.", offsetof(MOVMuxContext, iods_video_profile), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 255, AV_OPT_FLAG_ENCODING_PARAM},
    { "frag_duration", "Maximum fragment duration", offsetof(MOVMuxContext, max_fragment_duration), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
    { "min_frag_duration", "Minimum fragment duration", offsetof(MOVMuxContext, min_fragment_duration), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
    { "frag_size", "Maximum fragment size", offsetof(MOVMuxContext, max_fragment_size), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
    { "ism_lookahead", "Number of lookahead entries for ISM files", offsetof(MOVMuxContext, ism_lookahead), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
    { "video_track_timescale", "set timescale of all video tracks", offsetof(MOVMuxContext, video_track_timescale), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
    { "brand",    "Override major brand", offsetof(MOVMuxContext, major_brand),   AV_OPT_TYPE_STRING, {.str = NULL}, .flags = AV_OPT_FLAG_ENCODING_PARAM },
    { "use_editlist", "use edit list", offsetof(MOVMuxContext, use_editlist), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 1, AV_OPT_FLAG_ENCODING_PARAM},
    { "fragment_index", "Fragment number of the next fragment", offsetof(MOVMuxContext, fragments), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
    { NULL },
};

#define MOV_CLASS(flavor)\
static const AVClass flavor ## _muxer_class = {\
    .class_name = #flavor " muxer",\
    .item_name  = av_default_item_name,\
    .option     = options,\
    .version    = LIBAVUTIL_VERSION_INT,\
};

static int get_moov_size(AVFormatContext *s);

static int utf8len(const uint8_t *b)
{
    int len = 0;
    int val;
    while (*b) {
        GET_UTF8(val, *b++, return -1;)
        len++;
    }
    return len;
}

//FIXME support 64 bit variant with wide placeholders
static int64_t update_size(AVIOContext *pb, int64_t pos)
{
    int64_t curpos = avio_tell(pb);
    avio_seek(pb, pos, SEEK_SET);
    avio_wb32(pb, curpos - pos); /* rewrite size */
    avio_seek(pb, curpos, SEEK_SET);

    return curpos - pos;
}

static int co64_required(const MOVTrack *track)
{
    if (track->entry > 0 && track->cluster[track->entry - 1].pos + track->data_offset > UINT32_MAX)
        return 1;
    return 0;
}

/* Chunk offset atom */
static int mov_write_stco_tag(AVIOContext *pb, MOVTrack *track)
{
    int i;
    int mode64 = co64_required(track); // use 32 bit size variant if possible
    int64_t pos = avio_tell(pb);
    avio_wb32(pb, 0); /* size */
    if (mode64)
        ffio_wfourcc(pb, "co64");
    else
        ffio_wfourcc(pb, "stco");
    avio_wb32(pb, 0); /* version & flags */
    avio_wb32(pb, track->chunkCount); /* entry count */
    for (i = 0; i < track->entry; i++) {
        if (!track->cluster[i].chunkNum)
            continue;
        if (mode64 == 1)
            avio_wb64(pb, track->cluster[i].pos + track->data_offset);
        else
            avio_wb32(pb, track->cluster[i].pos + track->data_offset);
    }
    return update_size(pb, pos);
}

/* Sample size atom */
static int mov_write_stsz_tag(AVIOContext *pb, MOVTrack *track)
{
    int equalChunks = 1;
    int i, j, entries = 0, tst = -1, oldtst = -1;

    int64_t pos = avio_tell(pb);
    avio_wb32(pb, 0); /* size */
    ffio_wfourcc(pb, "stsz");
    avio_wb32(pb, 0); /* version & flags */

    for (i = 0; i < track->entry; i++) {
        tst = track->cluster[i].size / track->cluster[i].entries;
        if (oldtst != -1 && tst != oldtst)
            equalChunks = 0;
        oldtst = tst;
        entries += track->cluster[i].entries;
    }
    if (equalChunks && track->entry) {
        int sSize = track->entry ? track->cluster[0].size / track->cluster[0].entries : 0;
        sSize = FFMAX(1, sSize); // adpcm mono case could make sSize == 0
        avio_wb32(pb, sSize); // sample size
        avio_wb32(pb, entries); // sample count
    } else {
        avio_wb32(pb, 0); // sample size
        avio_wb32(pb, entries); // sample count
        for (i = 0; i < track->entry; i++) {
            for (j = 0; j < track->cluster[i].entries; j++) {
                avio_wb32(pb, track->cluster[i].size /
                          track->cluster[i].entries);
            }
        }
    }
    return update_size(pb, pos);
}

/* Sample to chunk atom */
static int mov_write_stsc_tag(AVIOContext *pb, MOVTrack *track)
{
    int index = 0, oldval = -1, i;
    int64_t entryPos, curpos;

    int64_t pos = avio_tell(pb);
    avio_wb32(pb, 0); /* size */
    ffio_wfourcc(pb, "stsc");
    avio_wb32(pb, 0); // version & flags
    entryPos = avio_tell(pb);
    avio_wb32(pb, track->chunkCount); // entry count
    for (i = 0; i < track->entry; i++) {
        if (oldval != track->cluster[i].samples_in_chunk && track->cluster[i].chunkNum) {
            avio_wb32(pb, track->cluster[i].chunkNum); // first chunk
            avio_wb32(pb, track->cluster[i].samples_in_chunk); // samples per chunk
            avio_wb32(pb, 0x1); // sample description index
            oldval = track->cluster[i].samples_in_chunk;
            index++;
        }
    }
    curpos = avio_tell(pb);
    avio_seek(pb, entryPos, SEEK_SET);
    avio_wb32(pb, index); // rewrite size
    avio_seek(pb, curpos, SEEK_SET);

    return update_size(pb, pos);
}

/* Sync sample atom */
static int mov_write_stss_tag(AVIOContext *pb, MOVTrack *track, uint32_t flag)
{
    int64_t curpos, entryPos;
    int i, index = 0;
    int64_t pos = avio_tell(pb);
    avio_wb32(pb, 0); // size
    ffio_wfourcc(pb, flag == MOV_SYNC_SAMPLE ? "stss" : "stps");
    avio_wb32(pb, 0); // version & flags
    entryPos = avio_tell(pb);
    avio_wb32(pb, track->entry); // entry count
    for (i = 0; i < track->entry; i++) {
        if (track->cluster[i].flags & flag) {
            avio_wb32(pb, i + 1);
            index++;
        }
    }
    curpos = avio_tell(pb);
    avio_seek(pb, entryPos, SEEK_SET);
    avio_wb32(pb, index); // rewrite size
    avio_seek(pb, curpos, SEEK_SET);
    return update_size(pb, pos);
}

static int mov_write_amr_tag(AVIOContext *pb, MOVTrack *track)
{
    avio_wb32(pb, 0x11); /* size */
    if (track->mode == MODE_MOV) ffio_wfourcc(pb, "samr");
    else                         ffio_wfourcc(pb, "damr");
    ffio_wfourcc(pb, "FFMP");
    avio_w8(pb, 0); /* decoder version */

    avio_wb16(pb, 0x81FF); /* Mode set (all modes for AMR_NB) */
    avio_w8(pb, 0x00); /* Mode change period (no restriction) */
    avio_w8(pb, 0x01); /* Frames per sample */
    return 0x11;
}

static int mov_write_ac3_tag(AVIOContext *pb, MOVTrack *track)
{
    GetBitContext gbc;
    PutBitContext pbc;
    uint8_t buf[3];
    int fscod, bsid, bsmod, acmod, lfeon, frmsizecod;

    if (track->vos_len < 7)
        return -1;

    avio_wb32(pb, 11);
    ffio_wfourcc(pb, "dac3");

    init_get_bits(&gbc, track->vos_data + 4, (track->vos_len - 4) * 8);
    fscod      = get_bits(&gbc, 2);
    frmsizecod = get_bits(&gbc, 6);
    bsid       = get_bits(&gbc, 5);
    bsmod      = get_bits(&gbc, 3);
    acmod      = get_bits(&gbc, 3);
    if (acmod == 2) {
        skip_bits(&gbc, 2); // dsurmod
    } else {
        if ((acmod & 1) && acmod != 1)
            skip_bits(&gbc, 2); // cmixlev
        if (acmod & 4)
            skip_bits(&gbc, 2); // surmixlev
    }
    lfeon = get_bits1(&gbc);

    init_put_bits(&pbc, buf, sizeof(buf));
    put_bits(&pbc, 2, fscod);
    put_bits(&pbc, 5, bsid);
    put_bits(&pbc, 3, bsmod);
    put_bits(&pbc, 3, acmod);
    put_bits(&pbc, 1, lfeon);
    put_bits(&pbc, 5, frmsizecod >> 1); // bit_rate_code
    put_bits(&pbc, 5, 0); // reserved

    flush_put_bits(&pbc);
    avio_write(pb, buf, sizeof(buf));

    return 11;
}

struct eac3_info {
    AVPacket pkt;
    uint8_t ec3_done;
    uint8_t num_blocks;

    /* Layout of the EC3SpecificBox */
    /* maximum bitrate */
    uint16_t data_rate;
    /* number of independent substreams */
    uint8_t  num_ind_sub;
    struct {
        /* sample rate code (see ff_ac3_sample_rate_tab) 2 bits */
        uint8_t fscod;
        /* bit stream identification 5 bits */
        uint8_t bsid;
        /* one bit reserved */
        /* audio service mixing (not supported yet) 1 bit */
        /* bit stream mode 3 bits */
        uint8_t bsmod;
        /* audio coding mode 3 bits */
        uint8_t acmod;
        /* sub woofer on 1 bit */
        uint8_t lfeon;
        /* 3 bits reserved */
        /* number of dependent substreams associated with this substream 4 bits */
        uint8_t num_dep_sub;
        /* channel locations of the dependent substream(s), if any, 9 bits */
        uint16_t chan_loc;
        /* if there is no dependent substream, then one bit reserved instead */
    } substream[1]; /* TODO: support 8 independent substreams */
};

static int handle_eac3(MOVMuxContext *mov, AVPacket *pkt, MOVTrack *track)
{
    GetBitContext gbc;
    AC3HeaderInfo tmp, *hdr = &tmp;
    struct eac3_info *info;
    int num_blocks;

    if (!track->eac3_priv && !(track->eac3_priv = av_mallocz(sizeof(*info))))
        return AVERROR(ENOMEM);
    info = track->eac3_priv;

    init_get_bits(&gbc, pkt->data, pkt->size * 8);
    if (avpriv_ac3_parse_header2(&gbc, &hdr) < 0) {
        /* drop the packets until we see a good one */
        if (!track->entry) {
            av_log(mov, AV_LOG_WARNING, "Dropping invalid packet from start of the stream\n");
            return 0;
        }
        return AVERROR_INVALIDDATA;
    }

    info->data_rate = FFMAX(info->data_rate, hdr->bit_rate / 1000);
    num_blocks = hdr->num_blocks;

    if (!info->ec3_done) {
        /* AC-3 substream must be the first one */
        if (hdr->bitstream_id <= 10 && hdr->substreamid != 0)
            return AVERROR(EINVAL);

        /* this should always be the case, given that our AC-3 parser
         * concatenates dependent frames to their independent parent */
        if (hdr->frame_type == EAC3_FRAME_TYPE_INDEPENDENT) {
            /* substream ids must be incremental */
            if (hdr->substreamid > info->num_ind_sub + 1)
                return AVERROR(EINVAL);

            if (hdr->substreamid == info->num_ind_sub + 1) {
                //info->num_ind_sub++;
                avpriv_request_sample(track->enc, "Multiple independent substreams");
                return AVERROR_PATCHWELCOME;
            } else if (hdr->substreamid < info->num_ind_sub ||
                       hdr->substreamid == 0 && info->substream[0].bsid) {
                info->ec3_done = 1;
                goto concatenate;
            }
        }

        /* fill the info needed for the "dec3" atom */
        info->substream[hdr->substreamid].fscod = hdr->sr_code;
        info->substream[hdr->substreamid].bsid  = hdr->bitstream_id;
        info->substream[hdr->substreamid].bsmod = hdr->bitstream_mode;
        info->substream[hdr->substreamid].acmod = hdr->channel_mode;
        info->substream[hdr->substreamid].lfeon = hdr->lfe_on;

        /* Parse dependent substream(s), if any */
        if (pkt->size != hdr->frame_size) {
            int cumul_size = hdr->frame_size;
            int parent = hdr->substreamid;

            while (cumul_size != pkt->size) {
                int i;
                init_get_bits(&gbc, pkt->data + cumul_size, (pkt->size - cumul_size) * 8);
                if (avpriv_ac3_parse_header2(&gbc, &hdr) < 0)
                    return AVERROR_INVALIDDATA;
                if (hdr->frame_type != EAC3_FRAME_TYPE_DEPENDENT)
                    return AVERROR(EINVAL);
                cumul_size += hdr->frame_size;
                info->substream[parent].num_dep_sub++;

                /* header is parsed up to lfeon, but custom channel map may be needed */
                /* skip bsid */
                skip_bits(&gbc, 5);
                /* skip volume control params */
                for (i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
                    skip_bits(&gbc, 5); // skip dialog normalization
                    if (get_bits1(&gbc)) {
                        skip_bits(&gbc, 8); // skip compression gain word
                    }
                }
                /* get the dependent stream channel map, if exists */
                if (get_bits1(&gbc))
                    info->substream[parent].chan_loc |= (get_bits(&gbc, 16) >> 5) & 0x1f;
                else
                    info->substream[parent].chan_loc |= hdr->channel_mode;
            }
        }
    }

concatenate:
    if (!info->num_blocks && num_blocks == 6)
        return pkt->size;
    else if (info->num_blocks + num_blocks > 6)
        return AVERROR_INVALIDDATA;

    if (!info->num_blocks) {
        int ret;
        if ((ret = av_copy_packet(&info->pkt, pkt)) < 0)
            return ret;
        info->num_blocks = num_blocks;
        return 0;
    } else {
        int ret;
        if ((ret = av_grow_packet(&info->pkt, pkt->size)) < 0)
            return ret;
        memcpy(info->pkt.data + info->pkt.size - pkt->size, pkt->data, pkt->size);
        info->num_blocks += num_blocks;
        info->pkt.duration += pkt->duration;
        if ((ret = av_copy_packet_side_data(&info->pkt, pkt)) < 0)
            return ret;
        if (info->num_blocks != 6)
            return 0;
        av_free_packet(pkt);
        if ((ret = av_copy_packet(pkt, &info->pkt)) < 0)
            return ret;
        av_free_packet(&info->pkt);
        info->num_blocks = 0;
    }

    return pkt->size;
}

static int mov_write_eac3_tag(AVIOContext *pb, MOVTrack *track)
{
    PutBitContext pbc;
    uint8_t *buf;
    struct eac3_info *info;
    int size, i;

    if (!track->eac3_priv)
        return AVERROR(EINVAL);

    info = track->eac3_priv;
    size = 2 + 4 * (info->num_ind_sub + 1);
    buf = av_malloc(size);
    if (!buf) {
        size = AVERROR(ENOMEM);
        goto end;
    }

    init_put_bits(&pbc, buf, size);
    put_bits(&pbc, 13, info->data_rate);
    put_bits(&pbc,  3, info->num_ind_sub);
    for (i = 0; i <= info->num_ind_sub; i++) {
        put_bits(&pbc, 2, info->substream[i].fscod);
        put_bits(&pbc, 5, info->substream[i].bsid);
        put_bits(&pbc, 1, 0); /* reserved */
        put_bits(&pbc, 1, 0); /* asvc */
        put_bits(&pbc, 3, info->substream[i].bsmod);
        put_bits(&pbc, 3, info->substream[i].acmod);
        put_bits(&pbc, 1, info->substream[i].lfeon);
        put_bits(&pbc, 5, 0); /* reserved */
        put_bits(&pbc, 4, info->substream[i].num_dep_sub);
        if (!info->substream[i].num_dep_sub) {
            put_bits(&pbc, 1, 0); /* reserved */
            size--;
        } else {
            put_bits(&pbc, 9, info->substream[i].chan_loc);
        }
    }
    flush_put_bits(&pbc);

    avio_wb32(pb, size + 8);
    ffio_wfourcc(pb, "dec3");
    avio_write(pb, buf, size);

    av_free(buf);

end:
    av_free_packet(&info->pkt);
    av_freep(&track->eac3_priv);

    return size;
}

/**
 * This function writes extradata "as is".
 * Extradata must be formatted like a valid atom (with size and tag).
 */
static int mov_write_extradata_tag(AVIOContext *pb, MOVTrack *track)
{
    avio_write(pb, track->enc->extradata, track->enc->extradata_size);
    return track->enc->extradata_size;
}

static int mov_write_enda_tag(AVIOContext *pb)
{
    avio_wb32(pb, 10);
    ffio_wfourcc(pb, "enda");
    avio_wb16(pb, 1); /* little endian */
    return 10;
}

static int mov_write_enda_tag_be(AVIOContext *pb)
{
  avio_wb32(pb, 10);
  ffio_wfourcc(pb, "enda");
  avio_wb16(pb, 0); /* big endian */
  return 10;
}

static void put_descr(AVIOContext *pb, int tag, unsigned int size)
{
    int i = 3;
    avio_w8(pb, tag);
    for (; i > 0; i--)
        avio_w8(pb, (size >> (7 * i)) | 0x80);
    avio_w8(pb, size & 0x7F);
}

static unsigned compute_avg_bitrate(MOVTrack *track)
{
    uint64_t size = 0;
    int i;
    if (!track->track_duration)
        return 0;
    for (i = 0; i < track->entry; i++)
        size += track->cluster[i].size;
    return size * 8 * track->timescale / track->track_duration;
}

static int mov_write_esds_tag(AVIOContext *pb, MOVTrack *track) // Basic
{
    int64_t pos = avio_tell(pb);
    int decoder_specific_info_len = track->vos_len ? 5 + track->vos_len : 0;
    unsigned avg_bitrate;

    avio_wb32(pb, 0); // size
    ffio_wfourcc(pb, "esds");
    avio_wb32(pb, 0); // Version

    // ES descriptor
    put_descr(pb, 0x03, 3 + 5+13 + decoder_specific_info_len + 5+1);
    avio_wb16(pb, track->track_id);
    avio_w8(pb, 0x00); // flags (= no flags)

    // DecoderConfig descriptor
    put_descr(pb, 0x04, 13 + decoder_specific_info_len);

    // Object type indication
    if ((track->enc->codec_id == AV_CODEC_ID_MP2 ||
         track->enc->codec_id == AV_CODEC_ID_MP3) &&
        track->enc->sample_rate > 24000)
        avio_w8(pb, 0x6B); // 11172-3
    else
        avio_w8(pb, ff_codec_get_tag(ff_mp4_obj_type, track->enc->codec_id));

    // the following fields is made of 6 bits to identify the streamtype (4 for video, 5 for audio)
    // plus 1 bit to indicate upstream and 1 bit set to 1 (reserved)
    if (track->enc->codec_id == AV_CODEC_ID_DVD_SUBTITLE)
        avio_w8(pb, (0x38 << 2) | 1); // flags (= NeroSubpicStream)
    else if (track->enc->codec_type == AVMEDIA_TYPE_AUDIO)
        avio_w8(pb, 0x15); // flags (= Audiostream)
    else
        avio_w8(pb, 0x11); // flags (= Visualstream)

    avio_wb24(pb, track->enc->rc_buffer_size >> 3); // Buffersize DB

    avg_bitrate = compute_avg_bitrate(track);
    // maxbitrate (FIXME should be max rate in any 1 sec window)
    avio_wb32(pb, FFMAX3(track->enc->bit_rate, track->enc->rc_max_rate, avg_bitrate));
    avio_wb32(pb, avg_bitrate);

    if (track->vos_len) {
        // DecoderSpecific info descriptor
        put_descr(pb, 0x05, track->vos_len);
        avio_write(pb, track->vos_data, track->vos_len);
    }

    // SL descriptor
    put_descr(pb, 0x06, 1);
    avio_w8(pb, 0x02);
    return update_size(pb, pos);
}

static int mov_pcm_le_gt16(enum AVCodecID codec_id)
{
    return codec_id == AV_CODEC_ID_PCM_S24LE ||
           codec_id == AV_CODEC_ID_PCM_S32LE ||
           codec_id == AV_CODEC_ID_PCM_F32LE ||
           codec_id == AV_CODEC_ID_PCM_F64LE;
}

static int mov_pcm_be_gt16(enum AVCodecID codec_id)
{
    return codec_id == AV_CODEC_ID_PCM_S24BE ||
           codec_id == AV_CODEC_ID_PCM_S32BE ||
           codec_id == AV_CODEC_ID_PCM_F32BE ||
           codec_id == AV_CODEC_ID_PCM_F64BE;
}

static int mov_write_ms_tag(AVIOContext *pb, MOVTrack *track)
{
    int ret;
    int64_t pos = avio_tell(pb);
    avio_wb32(pb, 0);
    avio_wl32(pb, track->tag); // store it byteswapped
    track->enc->codec_tag = av_bswap16(track->tag >> 16);
    if ((ret = ff_put_wav_header(pb, track->enc, 0)) < 0)
        return ret;
    return update_size(pb, pos);
}

static int mov_write_wfex_tag(AVIOContext *pb, MOVTrack *track)
{
    int ret;
    int64_t pos = avio_tell(pb);
    avio_wb32(pb, 0);
    ffio_wfourcc(pb, "wfex");
    if ((ret = ff_put_wav_header(pb, track->enc, FF_PUT_WAV_HEADER_FORCE_WAVEFORMATEX)) < 0)
        return ret;
    return update_size(pb, pos);
}

static int mov_write_chan_tag(AVIOContext *pb, MOVTrack *track)
{
    uint32_t layout_tag, bitmap;
    int64_t pos = avio_tell(pb);

    layout_tag = ff_mov_get_channel_layout_tag(track->enc->codec_id,
                                               track->enc->channel_layout,
                                               &bitmap);
    if (!layout_tag) {
        av_log(track->enc, AV_LOG_WARNING, "not writing 'chan' tag due to "
               "lack of channel information\n");
        return 0;
    }

    if (track->multichannel_as_mono)
        return 0;

    avio_wb32(pb, 0);           // Size
    ffio_wfourcc(pb, "chan");   // Type
    avio_w8(pb, 0);             // Version
    avio_wb24(pb, 0);           // Flags
    avio_wb32(pb, layout_tag);  // mChannelLayoutTag
    avio_wb32(pb, bitmap);      // mChannelBitmap
    avio_wb32(pb, 0);           // mNumberChannelDescriptions

    return update_size(pb, pos);
}

static int mov_write_wave_tag(AVIOContext *pb, MOVTrack *track)
{
    int64_t pos = avio_tell(pb);

    avio_wb32(pb, 0);     /* size */
    ffio_wfourcc(pb, "wave");

    if (track->enc->codec_id != AV_CODEC_ID_QDM2) {
    avio_wb32(pb, 12);    /* size */
    ffio_wfourcc(pb, "frma");
    avio_wl32(pb, track->tag);
    }

    if (track->enc->codec_id == AV_CODEC_ID_AAC) {
        /* useless atom needed by mplayer, ipod, not needed by quicktime */
        avio_wb32(pb, 12); /* size */
        ffio_wfourcc(pb, "mp4a");
        avio_wb32(pb, 0);
        mov_write_esds_tag(pb, track);
    } else if (mov_pcm_le_gt16(track->enc->codec_id))  {
      mov_write_enda_tag(pb);
    } else if (mov_pcm_be_gt16(track->enc->codec_id))  {
      mov_write_enda_tag_be(pb);
    } else if (track->enc->codec_id == AV_CODEC_ID_AMR_NB) {
        mov_write_amr_tag(pb, track);
    } else if (track->enc->codec_id == AV_CODEC_ID_AC3) {
        mov_write_ac3_tag(pb, track);
    } else if (track->enc->codec_id == AV_CODEC_ID_EAC3) {
        mov_write_eac3_tag(pb, track);
    } else if (track->enc->codec_id == AV_CODEC_ID_ALAC ||
               track->enc->codec_id == AV_CODEC_ID_QDM2) {
        mov_write_extradata_tag(pb, track);
    } else if (track->enc->codec_id == AV_CODEC_ID_ADPCM_MS ||
               track->enc->codec_id == AV_CODEC_ID_ADPCM_IMA_WAV) {
        mov_write_ms_tag(pb, track);
    }

    avio_wb32(pb, 8);     /* size */
    avio_wb32(pb, 0);     /* null tag */

    return update_size(pb, pos);
}

static int mov_write_dvc1_structs(MOVTrack *track, uint8_t *buf)
{
    uint8_t *unescaped;
    const uint8_t *start, *next, *end = track->vos_data + track->vos_len;
    int unescaped_size, seq_found = 0;
    int level = 0, interlace = 0;
    int packet_seq   = track->vc1_info.packet_seq;
    int packet_entry = track->vc1_info.packet_entry;
    int slices       = track->vc1_info.slices;
    PutBitContext pbc;

    if (track->start_dts == AV_NOPTS_VALUE) {
        /* No packets written yet, vc1_info isn't authoritative yet. */
        /* Assume inline sequence and entry headers. This will be
         * overwritten at the end if the file is seekable. */
        packet_seq = packet_entry = 1;
    }

    unescaped = av_mallocz(track->vos_len + FF_INPUT_BUFFER_PADDING_SIZE);
    if (!unescaped)
        return AVERROR(ENOMEM);
    start = find_next_marker(track->vos_data, end);
    for (next = start; next < end; start = next) {
        GetBitContext gb;
        int size;
        next = find_next_marker(start + 4, end);
        size = next - start - 4;
        if (size <= 0)
            continue;
        unescaped_size = vc1_unescape_buffer(start + 4, size, unescaped);
        init_get_bits(&gb, unescaped, 8 * unescaped_size);
        if (AV_RB32(start) == VC1_CODE_SEQHDR) {
            int profile = get_bits(&gb, 2);
            if (profile != PROFILE_ADVANCED) {
                av_free(unescaped);
                return AVERROR(ENOSYS);
            }
            seq_found = 1;
            level = get_bits(&gb, 3);
            /* chromaformat, frmrtq_postproc, bitrtq_postproc, postprocflag,
             * width, height */
            skip_bits_long(&gb, 2 + 3 + 5 + 1 + 2*12);
            skip_bits(&gb, 1); /* broadcast */
            interlace = get_bits1(&gb);
            skip_bits(&gb, 4); /* tfcntrflag, finterpflag, reserved, psf */
        }
    }
    if (!seq_found) {
        av_free(unescaped);
        return AVERROR(ENOSYS);
    }

    init_put_bits(&pbc, buf, 7);
    /* VC1DecSpecStruc */
    put_bits(&pbc, 4, 12); /* profile - advanced */
    put_bits(&pbc, 3, level);
    put_bits(&pbc, 1, 0); /* reserved */
    /* VC1AdvDecSpecStruc */
    put_bits(&pbc, 3, level);
    put_bits(&pbc, 1, 0); /* cbr */
    put_bits(&pbc, 6, 0); /* reserved */
    put_bits(&pbc, 1, !interlace); /* no interlace */
    put_bits(&pbc, 1, !packet_seq); /* no multiple seq */
    put_bits(&pbc, 1, !packet_entry); /* no multiple entry */
    put_bits(&pbc, 1, !slices); /* no slice code */
    put_bits(&pbc, 1, 0); /* no bframe */
    put_bits(&pbc, 1, 0); /* reserved */

    /* framerate */
    if (track->st->avg_frame_rate.num > 0 && track->st->avg_frame_rate.den > 0)
        put_bits32(&pbc, track->st->avg_frame_rate.num / track->st->avg_frame_rate.den);
    else
        put_bits32(&pbc, 0xffffffff);

    flush_put_bits(&pbc);

    av_free(unescaped);

    return 0;
}

static int mov_write_dvc1_tag(AVIOContext *pb, MOVTrack *track)
{
    uint8_t buf[7] = { 0 };
    int ret;

    if ((ret = mov_write_dvc1_structs(track, buf)) < 0)
        return ret;

    avio_wb32(pb, track->vos_len + 8 + sizeof(buf));
    ffio_wfourcc(pb, "dvc1");
    track->vc1_info.struct_offset = avio_tell(pb);
    avio_write(pb, buf, sizeof(buf));
    avio_write(pb, track->vos_data, track->vos_len);

    return 0;
}

static int mov_write_glbl_tag(AVIOContext *pb, MOVTrack *track)
{
    avio_wb32(pb, track->vos_len + 8);
    ffio_wfourcc(pb, "glbl");
    avio_write(pb, track->vos_data, track->vos_len);
    return 8 + track->vos_len;
}

/**
 * Compute flags for 'lpcm' tag.
 * See CoreAudioTypes and AudioStreamBasicDescription at Apple.
 */
static int mov_get_lpcm_flags(enum AVCodecID codec_id)
{
    switch (codec_id) {
    case AV_CODEC_ID_PCM_F32BE:
    case AV_CODEC_ID_PCM_F64BE:
        return 11;
    case AV_CODEC_ID_PCM_F32LE:
    case AV_CODEC_ID_PCM_F64LE:
        return 9;
    case AV_CODEC_ID_PCM_U8:
        return 10;
    case AV_CODEC_ID_PCM_S16BE:
    case AV_CODEC_ID_PCM_S24BE:
    case AV_CODEC_ID_PCM_S32BE:
        return 14;
    case AV_CODEC_ID_PCM_S8:
    case AV_CODEC_ID_PCM_S16LE:
    case AV_CODEC_ID_PCM_S24LE:
    case AV_CODEC_ID_PCM_S32LE:
        return 12;
    default:
        return 0;
    }
}

static int get_cluster_duration(MOVTrack *track, int cluster_idx)
{
    int64_t next_dts;

    if (cluster_idx >= track->entry)
        return 0;

    if (cluster_idx + 1 == track->entry)
        next_dts = track->track_duration + track->start_dts;
    else
        next_dts = track->cluster[cluster_idx + 1].dts;

    next_dts -= track->cluster[cluster_idx].dts;

    av_assert0(next_dts >= 0);
    av_assert0(next_dts <= INT_MAX);

    return next_dts;
}

static int get_samples_per_packet(MOVTrack *track)
{
    int i, first_duration;

// return track->enc->frame_size;

    /* use 1 for raw PCM */
    if (!track->audio_vbr)
        return 1;

    /* check to see if duration is constant for all clusters */
    if (!track->entry)
        return 0;
    first_duration = get_cluster_duration(track, 0);
    for (i = 1; i < track->entry; i++) {
        if (get_cluster_duration(track, i) != first_duration)
            return 0;
    }
    return first_duration;
}

static int mov_write_audio_tag(AVIOContext *pb, MOVTrack *track)
{
    int64_t pos = avio_tell(pb);
    int version = 0;
    uint32_t tag = track->tag;

    if (track->mode == MODE_MOV) {
        if (track->timescale > UINT16_MAX) {
            if (mov_get_lpcm_flags(track->enc->codec_id))
                tag = AV_RL32("lpcm");
            version = 2;
        } else if (track->audio_vbr || mov_pcm_le_gt16(track->enc->codec_id) ||
                   mov_pcm_be_gt16(track->enc->codec_id) ||
                   track->enc->codec_id == AV_CODEC_ID_ADPCM_MS ||
                   track->enc->codec_id == AV_CODEC_ID_ADPCM_IMA_WAV ||
                   track->enc->codec_id == AV_CODEC_ID_QDM2) {
            version = 1;
        }
    }

    avio_wb32(pb, 0); /* size */
    avio_wl32(pb, tag); // store it byteswapped
    avio_wb32(pb, 0); /* Reserved */
    avio_wb16(pb, 0); /* Reserved */
    avio_wb16(pb, 1); /* Data-reference index, XXX  == 1 */

    /* SoundDescription */
    avio_wb16(pb, version); /* Version */
    avio_wb16(pb, 0); /* Revision level */
    avio_wb32(pb, 0); /* Reserved */

    if (version == 2) {
        avio_wb16(pb, 3);
        avio_wb16(pb, 16);
        avio_wb16(pb, 0xfffe);
        avio_wb16(pb, 0);
        avio_wb32(pb, 0x00010000);
        avio_wb32(pb, 72);
        avio_wb64(pb, av_double2int(track->enc->sample_rate));
        avio_wb32(pb, track->enc->channels);
        avio_wb32(pb, 0x7F000000);
        avio_wb32(pb, av_get_bits_per_sample(track->enc->codec_id));
        avio_wb32(pb, mov_get_lpcm_flags(track->enc->codec_id));
        avio_wb32(pb, track->sample_size);
        avio_wb32(pb, get_samples_per_packet(track));
    } else {
        if (track->mode == MODE_MOV) {
            avio_wb16(pb, track->enc->channels);
            if (track->enc->codec_id == AV_CODEC_ID_PCM_U8 ||
                track->enc->codec_id == AV_CODEC_ID_PCM_S8)
                avio_wb16(pb, 8); /* bits per sample */
            else if (track->enc->codec_id == AV_CODEC_ID_ADPCM_G726)
                avio_wb16(pb, track->enc->bits_per_coded_sample);
            else
                avio_wb16(pb, 16);
            avio_wb16(pb, track->audio_vbr ? -2 : 0); /* compression ID */
        } else { /* reserved for mp4/3gp */
            avio_wb16(pb, 2);
            avio_wb16(pb, 16);
            avio_wb16(pb, 0);
        }

        avio_wb16(pb, 0); /* packet size (= 0) */
        avio_wb16(pb, track->enc->sample_rate <= UINT16_MAX ?
                      track->enc->sample_rate : 0);
        avio_wb16(pb, 0); /* Reserved */
    }

    if (version == 1) { /* SoundDescription V1 extended info */
        if (mov_pcm_le_gt16(track->enc->codec_id) ||
            mov_pcm_be_gt16(track->enc->codec_id))
            avio_wb32(pb, 1); /*  must be 1 for  uncompressed formats */
        else
            avio_wb32(pb, track->enc->frame_size); /* Samples per packet */
        avio_wb32(pb, track->sample_size / track->enc->channels); /* Bytes per packet */
        avio_wb32(pb, track->sample_size); /* Bytes per frame */
        avio_wb32(pb, 2); /* Bytes per sample */
    }

    if (track->mode == MODE_MOV &&
        (track->enc->codec_id == AV_CODEC_ID_AAC           ||
         track->enc->codec_id == AV_CODEC_ID_AC3           ||
         track->enc->codec_id == AV_CODEC_ID_EAC3          ||
         track->enc->codec_id == AV_CODEC_ID_AMR_NB        ||
         track->enc->codec_id == AV_CODEC_ID_ALAC          ||
         track->enc->codec_id == AV_CODEC_ID_ADPCM_MS      ||
         track->enc->codec_id == AV_CODEC_ID_ADPCM_IMA_WAV ||
         track->enc->codec_id == AV_CODEC_ID_QDM2          ||
         (mov_pcm_le_gt16(track->enc->codec_id) && version==1) ||
         (mov_pcm_be_gt16(track->enc->codec_id) && version==1)))
        mov_write_wave_tag(pb, track);
    else if (track->tag == MKTAG('m','p','4','a'))
        mov_write_esds_tag(pb, track);
    else if (track->enc->codec_id == AV_CODEC_ID_AMR_NB)
        mov_write_amr_tag(pb, track);
    else if (track->enc->codec_id == AV_CODEC_ID_AC3)
        mov_write_ac3_tag(pb, track);
    else if (track->enc->codec_id == AV_CODEC_ID_EAC3)
        mov_write_eac3_tag(pb, track);
    else if (track->enc->codec_id == AV_CODEC_ID_ALAC)
        mov_write_extradata_tag(pb, track);
    else if (track->enc->codec_id == AV_CODEC_ID_WMAPRO)
        mov_write_wfex_tag(pb, track);
    else if (track->vos_len > 0)
        mov_write_glbl_tag(pb, track);

    if (track->mode == MODE_MOV && track->enc->codec_type == AVMEDIA_TYPE_AUDIO)
        mov_write_chan_tag(pb, track);

    return update_size(pb, pos);
}

static int mov_write_d263_tag(AVIOContext *pb)
{
    avio_wb32(pb, 0xf); /* size */