/*

 * Flash Compatible Streaming Format demuxer

 * Copyright (c) 2000 Fabrice Bellard

 * Copyright (c) 2003 Tinic Uro

 *

 * 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 "config.h"

#if CONFIG_ZLIB

#include <zlib.h>

#endif

#include "libavutil/avassert.h"

#include "libavutil/channel_layout.h"

#include "libavutil/imgutils.h"

#include "libavutil/internal.h"

#include "libavutil/intreadwrite.h"

#include "libavutil/mem.h"

#include "libavcodec/get_bits.h"

#include "demux.h"

#include "swf.h"

#include "flv.h"

typedef struct SWFDecContext {

    int samples_per_frame;

    int frame_rate;

#if CONFIG_ZLIB

#define ZBUF_SIZE 4096

    AVIOContext *zpb;

    uint8_t *zbuf_in;

    uint8_t *zbuf_out;

    z_stream zstream;

#endif

} SWFDecContext;

static const AVCodecTag swf_audio_codec_tags[] = {

    { AV_CODEC_ID_PCM_S16LE,  0x00 },

    { AV_CODEC_ID_ADPCM_SWF,  0x01 },

    { AV_CODEC_ID_MP3,        0x02 },

    { AV_CODEC_ID_PCM_S16LE,  0x03 },

    { AV_CODEC_ID_NELLYMOSER, 0x06 },

    { AV_CODEC_ID_NONE,          0 },

};

static int get_swf_tag(AVIOContext *pb, int *len_ptr)

{

    int tag, len;

    if (avio_feof(pb))

        return AVERROR_EOF;

    tag = avio_rl16(pb);

    len = tag & 0x3f;

    tag = tag >> 6;

    if (len == 0x3f) {

        len = avio_rl32(pb);

    }

    *len_ptr = len;

    return tag;

}

static int swf_probe(const AVProbeData *p)

{

    GetBitContext gb;

    int len, xmin, xmax, ymin, ymax;

    if(p->buf_size < 15)

        return 0;

    /* check file header */

    if (   AV_RB24(p->buf) != AV_RB24("CWS")

        && AV_RB24(p->buf) != AV_RB24("FWS"))

        return 0;

    if (   AV_RB24(p->buf) == AV_RB24("CWS")

        && p->buf[3] <= 20)

        return AVPROBE_SCORE_MAX / 4 + 1;

    if (init_get_bits8(&gb, p->buf + 8, p->buf_size - 8) < 0)

        return 0;

    len = get_bits(&gb, 5);

    if (!len)

        return 0;

    xmin = get_bits_long(&gb, len);

    xmax = get_bits_long(&gb, len);

    ymin = get_bits_long(&gb, len);

    ymax = get_bits_long(&gb, len);

    if (xmin || ymin || !xmax || !ymax)

        return 0;

    if (p->buf[3] >= 20 || xmax < 16 || ymax < 16)

        return AVPROBE_SCORE_MAX / 4;

    return AVPROBE_SCORE_EXTENSION + 1;

}

#if CONFIG_ZLIB

static int zlib_refill(void *opaque, uint8_t *buf, int buf_size)

{

    AVFormatContext *s = opaque;

    SWFDecContext *swf = s->priv_data;

    z_stream *z = &swf->zstream;

    int ret;

retry:

    if (!z->avail_in) {

        int n = avio_read(s->pb, swf->zbuf_in, ZBUF_SIZE);

        if (n < 0)

            return n;

        z->next_in  = swf->zbuf_in;

        z->avail_in = n;

    }

    z->next_out  = buf;

    z->avail_out = buf_size;

    ret = inflate(z, Z_NO_FLUSH);

    if (ret == Z_STREAM_END)

        return AVERROR_EOF;

    if (ret != Z_OK)

        return AVERROR(EINVAL);

    if (buf_size - z->avail_out == 0)

        goto retry;

    return buf_size - z->avail_out;

}

static av_cold int swf_read_close(AVFormatContext *avctx);

#endif

static int swf_read_header(AVFormatContext *s)

{

    SWFDecContext *swf = s->priv_data;

    AVIOContext *pb = s->pb;

    int nbits, len, tag;

    tag = avio_rb32(pb) & 0xffffff00;

    avio_rl32(pb);

    if (tag == MKBETAG('C', 'W', 'S', 0)) {

        av_log(s, AV_LOG_INFO, "SWF compressed file detected\n");

#if CONFIG_ZLIB

        if (inflateInit(&swf->zstream) != Z_OK) {

            av_log(s, AV_LOG_ERROR, "Unable to init zlib context\n");

            return AVERROR(EINVAL);

        }

        if (!(swf->zbuf_in  = av_malloc(ZBUF_SIZE)) ||

            !(swf->zbuf_out = av_malloc(ZBUF_SIZE)) ||

            !(swf->zpb = avio_alloc_context(swf->zbuf_out, ZBUF_SIZE, 0,

                                            s, zlib_refill, NULL, NULL))) {

            swf_read_close(s);

            return AVERROR(ENOMEM);

        }

        swf->zpb->seekable = 0;

        pb = swf->zpb;

#else

        av_log(s, AV_LOG_ERROR, "zlib support is required to read SWF compressed files\n");

        return AVERROR(ENOSYS);

#endif

    } else if (tag != MKBETAG('F', 'W', 'S', 0))

        return AVERROR_INVALIDDATA;

    /* skip rectangle size */

    nbits = avio_r8(pb) >> 3;

    len = (4 * nbits - 3 + 7) / 8;

    avio_skip(pb, len);

    swf->frame_rate = avio_rl16(pb); /* 8.8 fixed */

    avio_rl16(pb); /* frame count */

    swf->samples_per_frame = 0;

    s->ctx_flags |= AVFMTCTX_NOHEADER;

    return 0;

}

static AVStream *create_new_audio_stream(AVFormatContext *s, int id, int info)

{

    int sample_rate_code, sample_size_code;

    AVStream *ast = avformat_new_stream(s, NULL);

    if (!ast)

        return NULL;

    ast->id = id;

    av_channel_layout_default(&ast->codecpar->ch_layout, 1 + (info & 1));

    ast->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;

    ast->codecpar->codec_id   = ff_codec_get_id(swf_audio_codec_tags, info>>4 & 15);

    ffstream(ast)->need_parsing = AVSTREAM_PARSE_FULL;

    sample_rate_code = info>>2 & 3;

    sample_size_code = info>>1 & 1;

    if (!sample_size_code && ast->codecpar->codec_id == AV_CODEC_ID_PCM_S16LE)

        ast->codecpar->codec_id = AV_CODEC_ID_PCM_U8;

    ast->codecpar->sample_rate = 44100 >> (3 - sample_rate_code);

    avpriv_set_pts_info(ast, 64, 1, ast->codecpar->sample_rate);

    return ast;

}

static int swf_read_packet(AVFormatContext *s, AVPacket *pkt)

{

    SWFDecContext *swf = s->priv_data;

    AVIOContext *pb = s->pb;

    AVStream *vst = NULL, *ast = NULL, *st = 0;

    int tag, len, i, frame, v, res;

#if CONFIG_ZLIB

    if (swf->zpb)

        pb = swf->zpb;

#endif

    for(;;) {

        uint64_t pos = avio_tell(pb);

        tag = get_swf_tag(pb, &len);

        if (tag < 0)

            return tag;

        if (len < 0) {

            av_log(s, AV_LOG_ERROR, "invalid tag length: %d\n", len);

            return AVERROR_INVALIDDATA;

        }

        if (tag == TAG_VIDEOSTREAM) {

            int ch_id = avio_rl16(pb);

            len -= 2;

            for (i=0; i<s->nb_streams; i++) {

                st = s->streams[i];

                if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && st->id == ch_id)

                    goto skip;

            }

            avio_rl16(pb);

            avio_rl16(pb);

            avio_rl16(pb);

            avio_r8(pb);

            /* Check for FLV1 */

            vst = avformat_new_stream(s, NULL);

            if (!vst)

                return AVERROR(ENOMEM);

            vst->id = ch_id;

            vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;

            vst->codecpar->codec_id = ff_codec_get_id(ff_swf_codec_tags, avio_r8(pb));

            avpriv_set_pts_info(vst, 16, 256, swf->frame_rate);

            len -= 8;

        } else if (tag == TAG_STREAMHEAD || tag == TAG_STREAMHEAD2) {

            /* streaming found */

            for (i=0; i<s->nb_streams; i++) {

                st = s->streams[i];

                if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO && st->id == -1)

                    goto skip;

            }

            avio_r8(pb);

            v = avio_r8(pb);

            swf->samples_per_frame = avio_rl16(pb);

            ast = create_new_audio_stream(s, -1, v); /* -1 to avoid clash with video stream ch_id */

            if (!ast)

                return AVERROR(ENOMEM);

            len -= 4;

        } else if (tag == TAG_DEFINESOUND) {

            /* audio stream */

            int ch_id = avio_rl16(pb);

            for (i=0; i<s->nb_streams; i++) {

                st = s->streams[i];

                if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO && st->id == ch_id)

                    goto skip;

            }

            // FIXME: The entire audio stream is stored in a single chunk/tag. Normally,

            // these are smaller audio streams in DEFINESOUND tags, but it's technically

            // possible they could be huge. Break it up into multiple packets if it's big.

            v = avio_r8(pb);

            ast = create_new_audio_stream(s, ch_id, v);

            if (!ast)

                return AVERROR(ENOMEM);

            ast->duration = avio_rl32(pb); // number of samples

            if (((v>>4) & 15) == 2) { // MP3 sound data record

                ffstream(ast)->skip_samples = avio_rl16(pb);

                len -= 2;

            }

            len -= 7;

            if ((res = av_get_packet(pb, pkt, len)) < 0)

                return res;

            pkt->pos = pos;

            pkt->stream_index = ast->index;

            return pkt->size;

        } else if (tag == TAG_VIDEOFRAME) {

            int ch_id = avio_rl16(pb);

            len -= 2;

            for(i=0; i<s->nb_streams; i++) {

                st = s->streams[i];

                if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && st->id == ch_id) {

                    int pkt_flags = 0;

                    frame = avio_rl16(pb);

                    len -= 2;

                    if (len <= 0)

                        goto skip;

                    if (st->codecpar->codec_id == AV_CODEC_ID_FLASHSV) {

                        unsigned flags = avio_r8(pb);

                        len--;

                        if (len <= 0)

                            goto skip;

                        pkt_flags |= (flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY ? AV_PKT_FLAG_KEY : 0;

                    }

                    if ((res = av_get_packet(pb, pkt, len)) < 0)

                        return res;

                    pkt->pos = pos;

                    pkt->pts = frame;

                    pkt->stream_index = st->index;

                    pkt->flags |= pkt_flags;

                    return pkt->size;

                }

            }

        } else if (tag == TAG_DEFINEBITSLOSSLESS || tag == TAG_DEFINEBITSLOSSLESS2) {

#if CONFIG_ZLIB

            long out_len;

            uint8_t *buf = NULL, *zbuf = NULL, *pal;

            uint32_t colormap[AVPALETTE_COUNT] = {0};

            const int alpha_bmp = tag == TAG_DEFINEBITSLOSSLESS2;

            const int colormapbpp = 3 + alpha_bmp;

            int linesize, colormapsize = 0;

            const int ch_id   = avio_rl16(pb);

            const int bmp_fmt = avio_r8(pb);

            const int width   = avio_rl16(pb);

            const int height  = avio_rl16(pb);

            int pix_fmt;

            len -= 2+1+2+2;

            switch (bmp_fmt) {

            case 3: // PAL-8

                linesize = width;

                colormapsize = avio_r8(pb) + 1;

                len--;

                break;

            case 4: // RGB15

                linesize = width * 2;

                break;

            case 5: // RGB24 (0RGB)

                linesize = width * 4;

                break;

            default:

                av_log(s, AV_LOG_ERROR, "invalid bitmap format %d, skipped\n", bmp_fmt);

                goto bitmap_end_skip;

            }

            linesize = FFALIGN(linesize, 4);

            if (av_image_check_size(width, height, 0, s) < 0 ||

                linesize >= INT_MAX / height ||

                linesize * height >= INT_MAX - colormapsize * colormapbpp) {

                av_log(s, AV_LOG_ERROR, "invalid frame size %dx%d\n", width, height);

                goto bitmap_end_skip;

            }

            out_len = colormapsize * colormapbpp + linesize * height;

            ff_dlog(s, "bitmap: ch=%d fmt=%d %dx%d (linesize=%d) len=%d->%ld pal=%d\n",

                    ch_id, bmp_fmt, width, height, linesize, len, out_len, colormapsize);

            if (len * 17373LL < out_len)

                goto bitmap_end_skip;

            zbuf = av_malloc(len);

            if (!zbuf) {

                res = AVERROR(ENOMEM);

                goto bitmap_end;

            }

            len = avio_read(pb, zbuf, len);

            if (len < 0)

                goto bitmap_end_skip;

            buf  = av_malloc(out_len);

            if (!buf) {

                res = AVERROR(ENOMEM);

                goto bitmap_end;

            }

            if ((res = uncompress(buf, &out_len, zbuf, len)) != Z_OK) {

                av_log(s, AV_LOG_WARNING, "Failed to uncompress one bitmap\n");

                goto bitmap_end_skip;

            }

            for (i = 0; i < s->nb_streams; i++) {

                st = s->streams[i];

                if (st->codecpar->codec_id == AV_CODEC_ID_RAWVIDEO && st->id == -3)

                    break;

            }

            if (i == s->nb_streams) {

                vst = avformat_new_stream(s, NULL);

                if (!vst) {

                    res = AVERROR(ENOMEM);

                    goto bitmap_end;

                }

                vst->id = -3; /* -3 to avoid clash with video stream and audio stream */

                vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;

                vst->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;

                avpriv_set_pts_info(vst, 64, 256, swf->frame_rate);

                st = vst;

            }

            if ((res = av_new_packet(pkt, out_len - colormapsize * colormapbpp)) < 0)

                goto bitmap_end;

            if (!st->codecpar->width && !st->codecpar->height) {

                st->codecpar->width  = width;

                st->codecpar->height = height;

            } else {

                ff_add_param_change(pkt, 0, 0, 0, width, height);

            }

            pkt->pos = pos;

            pkt->stream_index = st->index;

            if (linesize * height > pkt->size) {

                res = AVERROR_INVALIDDATA;

                goto bitmap_end;

            }

            switch (bmp_fmt) {

            case 3:

                pix_fmt = AV_PIX_FMT_PAL8;

                for (i = 0; i < colormapsize; i++)

                    if (alpha_bmp)  colormap[i] = buf[3]<<24 | AV_RB24(buf + 4*i);

                    else            colormap[i] = 0xffU <<24 | AV_RB24(buf + 3*i);

                pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, AVPALETTE_SIZE);

                if (!pal) {

                    res = AVERROR(ENOMEM);

                    goto bitmap_end;

                }

                memcpy(pal, colormap, AVPALETTE_SIZE);

                break;

            case 4:

                pix_fmt = AV_PIX_FMT_RGB555;

                break;

            case 5:

                pix_fmt = alpha_bmp ? AV_PIX_FMT_ARGB : AV_PIX_FMT_0RGB;

                break;

            default:

                av_assert0(0);

            }

            if (st->codecpar->format != AV_PIX_FMT_NONE && st->codecpar->format != pix_fmt) {

                av_log(s, AV_LOG_ERROR, "pixel format change unsupported\n");

            } else

                st->codecpar->format = pix_fmt;

            memcpy(pkt->data, buf + colormapsize*colormapbpp, linesize * height);

            res = pkt->size;

bitmap_end:

            av_freep(&zbuf);

            av_freep(&buf);

            return res;

bitmap_end_skip:

            av_freep(&zbuf);

            av_freep(&buf);

#else

            av_log(s, AV_LOG_ERROR, "this file requires zlib support compiled in\n");

#endif

        } else if (tag == TAG_STREAMBLOCK) {

            for (i = 0; i < s->nb_streams; i++) {

                st = s->streams[i];

                if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO && st->id == -1) {

                    if (st->codecpar->codec_id == AV_CODEC_ID_MP3) {

                        avio_skip(pb, 4);

                        len -= 4;

                        if (len <= 0)

                            goto skip;

                        if ((res = av_get_packet(pb, pkt, len)) < 0)

                            return res;

                    } else { // ADPCM, PCM

                        if (len <= 0)

                            goto skip;

                        if ((res = av_get_packet(pb, pkt, len)) < 0)

                            return res;

                    }

                    pkt->pos          = pos;

                    pkt->stream_index = st->index;

                    return pkt->size;

                }

            }

        } else if (tag == TAG_JPEG2) {

            for (i=0; i<s->nb_streams; i++) {

                st = s->streams[i];

                if (st->codecpar->codec_id == AV_CODEC_ID_MJPEG && st->id == -2)

                    break;

            }

            if (i == s->nb_streams) {

                vst = avformat_new_stream(s, NULL);

                if (!vst)

                    return AVERROR(ENOMEM);

                vst->id = -2; /* -2 to avoid clash with video stream and audio stream */

                vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;

                vst->codecpar->codec_id = AV_CODEC_ID_MJPEG;

                avpriv_set_pts_info(vst, 64, 256, swf->frame_rate);

                st = vst;

            }

            avio_rl16(pb); /* BITMAP_ID */

            len -= 2;

            if (len < 4)

                goto skip;

            if ((res = av_new_packet(pkt, len)) < 0)

                return res;

            if (avio_read(pb, pkt->data, 4) != 4) {

                return AVERROR_INVALIDDATA;

            }

            if (AV_RB32(pkt->data) == 0xffd8ffd9 ||

                AV_RB32(pkt->data) == 0xffd9ffd8) {

                /* old SWF files containing SOI/EOI as data start */

                /* files created by swink have reversed tag */

                pkt->size -= 4;

                memset(pkt->data+pkt->size, 0, 4);

                res = avio_read(pb, pkt->data, pkt->size);

            } else {

                res = avio_read(pb, pkt->data + 4, pkt->size - 4);

                if (res >= 0)

                    res += 4;

            }

            if (res != pkt->size) {

                if (res < 0) {

                    return res;

                }

                av_shrink_packet(pkt, res);

            }

            pkt->pos = pos;

            pkt->stream_index = st->index;

            return pkt->size;

        } else {

            av_log(s, AV_LOG_DEBUG, "Unknown tag: %d\n", tag);

        }

    skip:

        if(len<0)

            av_log(s, AV_LOG_WARNING, "Clipping len %d\n", len);

        len = FFMAX(0, len);

        avio_skip(pb, len);

    }

}

#if CONFIG_ZLIB

static av_cold int swf_read_close(AVFormatContext *avctx)

{

    SWFDecContext *s = avctx->priv_data;

    inflateEnd(&s->zstream);

    av_freep(&s->zbuf_in);

    av_freep(&s->zbuf_out);

    avio_context_free(&s->zpb);

    return 0;

}

#endif

const FFInputFormat ff_swf_demuxer = {

    .p.name         = "swf",

    .p.long_name    = NULL_IF_CONFIG_SMALL("SWF (ShockWave Flash)"),

    .priv_data_size = sizeof(SWFDecContext),

    .read_probe     = swf_probe,

    .read_header    = swf_read_header,

    .read_packet    = swf_read_packet,

#if CONFIG_ZLIB

    .read_close     = swf_read_close,

#endif

};