/*

 * YUV4MPEG demuxer

 * Copyright (c) 2001, 2002, 2003 Fabrice Bellard

 *

 * 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 "libavutil/avstring.h"

#include "libavutil/imgutils.h"

#include "avformat.h"

#include "demux.h"

#include "internal.h"

#include "yuv4mpeg.h"

/* Header size increased to allow room for optional flags */

#define MAX_YUV4_HEADER 128

#define MAX_FRAME_HEADER 80

static int yuv4_read_header(AVFormatContext *s)

{

    char header[MAX_YUV4_HEADER + 10];  // Include headroom for

                                        // the longest option

    char *tokstart, *tokend, *header_end;

    AVIOContext *pb = s->pb;

    int width = -1, height  = -1, raten   = 0,

        rated =  0, aspectn =  0, aspectd = 0;

    enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE, alt_pix_fmt = AV_PIX_FMT_NONE;

    enum AVChromaLocation chroma_sample_location = AVCHROMA_LOC_UNSPECIFIED;

    enum AVFieldOrder field_order = AV_FIELD_UNKNOWN;

    enum AVColorRange color_range = AVCOL_RANGE_UNSPECIFIED;

    AVStream *st;

    int64_t data_offset;

    for (int i = 0;;) {

        header[i] = avio_r8(pb);

        if (header[i] == '\n') {

            header[i + 1] = 0x20;  // Add a space after last option.

                                   // Makes parsing "444" vs "444alpha" easier.

            header[i + 2] = 0;

            header_end = &header[i + 1]; // Include space

            break;

        }

        if (++i == MAX_YUV4_HEADER) {

            av_log(s, AV_LOG_ERROR, "Header too large.\n");

            return AVERROR(EINVAL);

        }

    }

    if (strncmp(header, Y4M_MAGIC, strlen(Y4M_MAGIC))) {

        av_log(s, AV_LOG_ERROR, "Invalid magic number for yuv4mpeg.\n");

        return AVERROR(EINVAL);

    }

    for (tokstart = &header[strlen(Y4M_MAGIC) + 1];

         tokstart < header_end; tokstart++) {

        if (*tokstart == 0x20)

            continue;

        switch (*tokstart++) {

        case 'W': // Width. Required.

            width    = strtol(tokstart, &tokend, 10);

            tokstart = tokend;

            break;

        case 'H': // Height. Required.

            height   = strtol(tokstart, &tokend, 10);

            tokstart = tokend;

            break;

        case 'C': // Color space

        {

            static const struct {

#define MAX_PIX_FMT_LENGTH 8

                char name[MAX_PIX_FMT_LENGTH + 1];

#undef MAX_PIX_FMT_LENGTH

                enum AVPixelFormat pix_fmt;

                enum AVChromaLocation chroma_loc;

            } pix_fmt_array[] = {

                { "420jpeg",  AV_PIX_FMT_YUV420P,   AVCHROMA_LOC_CENTER      },

                { "420mpeg2", AV_PIX_FMT_YUV420P,   AVCHROMA_LOC_LEFT        },

                { "420paldv", AV_PIX_FMT_YUV420P,   AVCHROMA_LOC_TOPLEFT     },

                { "420p16",   AV_PIX_FMT_YUV420P16, AVCHROMA_LOC_UNSPECIFIED },

                { "422p16",   AV_PIX_FMT_YUV422P16, AVCHROMA_LOC_UNSPECIFIED },

                { "444p16",   AV_PIX_FMT_YUV444P16, AVCHROMA_LOC_UNSPECIFIED },

                { "420p14",   AV_PIX_FMT_YUV420P14, AVCHROMA_LOC_UNSPECIFIED },

                { "422p14",   AV_PIX_FMT_YUV422P14, AVCHROMA_LOC_UNSPECIFIED },

                { "444p14",   AV_PIX_FMT_YUV444P14, AVCHROMA_LOC_UNSPECIFIED },

                { "420p12",   AV_PIX_FMT_YUV420P12, AVCHROMA_LOC_UNSPECIFIED },

                { "422p12",   AV_PIX_FMT_YUV422P12, AVCHROMA_LOC_UNSPECIFIED },

                { "444p12",   AV_PIX_FMT_YUV444P12, AVCHROMA_LOC_UNSPECIFIED },

                { "420p10",   AV_PIX_FMT_YUV420P10, AVCHROMA_LOC_UNSPECIFIED },

                { "422p10",   AV_PIX_FMT_YUV422P10, AVCHROMA_LOC_UNSPECIFIED },

                { "444p10",   AV_PIX_FMT_YUV444P10, AVCHROMA_LOC_UNSPECIFIED },

                { "420p9",    AV_PIX_FMT_YUV420P9,  AVCHROMA_LOC_UNSPECIFIED },

                { "422p9",    AV_PIX_FMT_YUV422P9,  AVCHROMA_LOC_UNSPECIFIED },

                { "444p9",    AV_PIX_FMT_YUV444P9,  AVCHROMA_LOC_UNSPECIFIED },

                { "420",      AV_PIX_FMT_YUV420P,   AVCHROMA_LOC_CENTER      },

                { "411",      AV_PIX_FMT_YUV411P,   AVCHROMA_LOC_UNSPECIFIED },

                { "422",      AV_PIX_FMT_YUV422P,   AVCHROMA_LOC_UNSPECIFIED },

                { "444alpha", AV_PIX_FMT_YUVA444P,  AVCHROMA_LOC_UNSPECIFIED },

                { "444",      AV_PIX_FMT_YUV444P,   AVCHROMA_LOC_UNSPECIFIED },

                { "mono16",   AV_PIX_FMT_GRAY16,    AVCHROMA_LOC_UNSPECIFIED },

                { "mono12",   AV_PIX_FMT_GRAY12,    AVCHROMA_LOC_UNSPECIFIED },

                { "mono10",   AV_PIX_FMT_GRAY10,    AVCHROMA_LOC_UNSPECIFIED },

                { "mono9",    AV_PIX_FMT_GRAY9,     AVCHROMA_LOC_UNSPECIFIED },

                { "mono",     AV_PIX_FMT_GRAY8,     AVCHROMA_LOC_UNSPECIFIED },

            };

            size_t i;

            for (i = 0; i < FF_ARRAY_ELEMS(pix_fmt_array); i++) {

                if (av_strstart(tokstart, pix_fmt_array[i].name, NULL)) {

                    pix_fmt = pix_fmt_array[i].pix_fmt;

                    if (pix_fmt_array[i].chroma_loc != AVCHROMA_LOC_UNSPECIFIED)

                        chroma_sample_location = pix_fmt_array[i].chroma_loc;

                    break;

                }

            }

            if (i == FF_ARRAY_ELEMS(pix_fmt_array)) {

                av_log(s, AV_LOG_ERROR, "YUV4MPEG stream contains an unknown "

                       "pixel format.\n");

                return AVERROR_INVALIDDATA;

            }

            while (tokstart < header_end && *tokstart != 0x20)

                tokstart++;

            break;

        }

        case 'I': // Interlace type

            switch (*tokstart++){

            case '?':

                field_order = AV_FIELD_UNKNOWN;

                break;

            case 'p':

                field_order = AV_FIELD_PROGRESSIVE;

                break;

            case 't':

                field_order = AV_FIELD_TT;

                break;

            case 'b':

                field_order = AV_FIELD_BB;

                break;

            case 'm':

                av_log(s, AV_LOG_ERROR, "YUV4MPEG stream contains mixed "

                       "interlaced and non-interlaced frames.\n");

                return AVERROR(ENOTSUP);

            default:

                av_log(s, AV_LOG_ERROR, "YUV4MPEG has invalid header.\n");

                return AVERROR(EINVAL);

            }

            break;

        case 'F': // Frame rate

            sscanf(tokstart, "%d:%d", &raten, &rated); // 0:0 if unknown

            while (tokstart < header_end && *tokstart != 0x20)

                tokstart++;

            break;

        case 'A': // Pixel aspect

            sscanf(tokstart, "%d:%d", &aspectn, &aspectd); // 0:0 if unknown

            while (tokstart < header_end && *tokstart != 0x20)

                tokstart++;

            break;

        case 'X': // Vendor extensions

            if (strncmp("YSCSS=", tokstart, 6) == 0) {

                static const struct {

#define MAX_PIX_FMT_LENGTH 8

                    char name[MAX_PIX_FMT_LENGTH + 1];

#undef MAX_PIX_FMT_LENGTH

                    enum AVPixelFormat pix_fmt;

                } pix_fmt_array[] = {

                    { "420JPEG",  AV_PIX_FMT_YUV420P   },

                    { "420MPEG2", AV_PIX_FMT_YUV420P   },

                    { "420PALDV", AV_PIX_FMT_YUV420P   },

                    { "420P9",    AV_PIX_FMT_YUV420P9  },

                    { "422P9",    AV_PIX_FMT_YUV422P9  },

                    { "444P9",    AV_PIX_FMT_YUV444P9  },

                    { "420P10",   AV_PIX_FMT_YUV420P10 },

                    { "444P10",   AV_PIX_FMT_YUV444P10 },

                    { "420P12",   AV_PIX_FMT_YUV420P12 },

                    { "422P12",   AV_PIX_FMT_YUV422P12 },

                    { "444P12",   AV_PIX_FMT_YUV444P12 },

                    { "420P14",   AV_PIX_FMT_YUV420P14 },

                    { "422P14",   AV_PIX_FMT_YUV422P14 },

                    { "444P14",   AV_PIX_FMT_YUV444P14 },

                    { "420P16",   AV_PIX_FMT_YUV420P16 },

                    { "422P16",   AV_PIX_FMT_YUV422P16 },

                    { "444P16",   AV_PIX_FMT_YUV444P16 },

                    { "411",      AV_PIX_FMT_YUV411P   },

                    { "422",      AV_PIX_FMT_YUV422P   },

                    { "444",      AV_PIX_FMT_YUV444P   },

                };

                // Older nonstandard pixel format representation

                tokstart += 6;

                for (size_t i = 0; i < FF_ARRAY_ELEMS(pix_fmt_array); i++)

                    if (av_strstart(tokstart, pix_fmt_array[i].name, NULL)) {

                        alt_pix_fmt = pix_fmt_array[i].pix_fmt;

                        break;

                    }

            } else if (strncmp("COLORRANGE=", tokstart, 11) == 0) {

              tokstart += 11;

              if (strncmp("FULL",tokstart, 4) == 0)

                  color_range = AVCOL_RANGE_JPEG;

              else if (strncmp("LIMITED", tokstart, 7) == 0)

                  color_range = AVCOL_RANGE_MPEG;

            }

            while (tokstart < header_end && *tokstart != 0x20)

                tokstart++;

            break;

        }

    }

    if (width == -1 || height == -1) {

        av_log(s, AV_LOG_ERROR, "YUV4MPEG has invalid header.\n");

        return AVERROR_INVALIDDATA;

    }

    if (pix_fmt == AV_PIX_FMT_NONE) {

        if (alt_pix_fmt == AV_PIX_FMT_NONE)

            pix_fmt = AV_PIX_FMT_YUV420P;

        else

            pix_fmt = alt_pix_fmt;

    }

    if (raten <= 0 || rated <= 0) {

        // Frame rate unknown

        raten = 25;

        rated = 1;

    }

    if (aspectn == 0 && aspectd == 0) {

        // Pixel aspect unknown

        aspectd = 1;

    }

    st = avformat_new_stream(s, NULL);

    if (!st)

        return AVERROR(ENOMEM);

    st->codecpar->width  = width;

    st->codecpar->height = height;

    av_reduce(&raten, &rated, raten, rated, (1UL << 31) - 1);

    avpriv_set_pts_info(st, 64, rated, raten);

    st->avg_frame_rate                = av_inv_q(st->time_base);

    st->codecpar->format              = pix_fmt;

    st->codecpar->codec_type          = AVMEDIA_TYPE_VIDEO;

    st->codecpar->codec_id            = AV_CODEC_ID_RAWVIDEO;

    st->sample_aspect_ratio           = (AVRational){ aspectn, aspectd };

    st->codecpar->chroma_location     = chroma_sample_location;

    st->codecpar->color_range         = color_range;

    st->codecpar->field_order         = field_order;

    s->packet_size = av_image_get_buffer_size(st->codecpar->format, width, height, 1) + Y4M_FRAME_MAGIC_LEN;

    if ((int) s->packet_size < 0)

        return s->packet_size;

    ffformatcontext(s)->data_offset = data_offset = avio_tell(pb);

    st->duration = (avio_size(pb) - data_offset) / s->packet_size;

    return 0;

}

static int yuv4_read_packet(AVFormatContext *s, AVPacket *pkt)

{

    int i;

    char header[MAX_FRAME_HEADER+1];

    int ret;

    int64_t off = avio_tell(s->pb);

    for (i = 0; i < MAX_FRAME_HEADER; i++) {

        header[i] = avio_r8(s->pb);

        if (header[i] == '\n') {

            header[i + 1] = 0;

            break;

        }

    }

    if (s->pb->error)

        return s->pb->error;

    else if (s->pb->eof_reached)

        return AVERROR_EOF;

    else if (i == MAX_FRAME_HEADER)

        return AVERROR_INVALIDDATA;

    if (strncmp(header, Y4M_FRAME_MAGIC, strlen(Y4M_FRAME_MAGIC)))

        return AVERROR_INVALIDDATA;

    ret = av_get_packet(s->pb, pkt, s->packet_size - Y4M_FRAME_MAGIC_LEN);

    if (ret < 0)

        return ret;

    else if (ret != s->packet_size - Y4M_FRAME_MAGIC_LEN) {

        return s->pb->eof_reached ? AVERROR_EOF : AVERROR_INVALIDDATA;

    }

    pkt->stream_index = 0;

    pkt->pts = (off - ffformatcontext(s)->data_offset) / s->packet_size;

    pkt->duration = 1;

    return 0;

}

static int yuv4_read_seek(AVFormatContext *s, int stream_index,

                          int64_t pts, int flags)

{

    int64_t pos;

    if (flags & AVSEEK_FLAG_BACKWARD)

        pts = FFMAX(0, pts - 1);

    if (pts < 0)

        return -1;

    pos = pts * s->packet_size;

    if (avio_seek(s->pb, pos + ffformatcontext(s)->data_offset, SEEK_SET) < 0)

        return -1;

    return 0;

}

static int yuv4_probe(const AVProbeData *pd)

{

    /* check file header */

    if (strncmp(pd->buf, Y4M_MAGIC, sizeof(Y4M_MAGIC) - 1) == 0)

        return AVPROBE_SCORE_MAX;

    else

        return 0;

}

const FFInputFormat ff_yuv4mpegpipe_demuxer = {

    .p.name         = "yuv4mpegpipe",

    .p.long_name    = NULL_IF_CONFIG_SMALL("YUV4MPEG pipe"),

    .p.extensions   = "y4m",

    .read_probe     = yuv4_probe,

    .read_header    = yuv4_read_header,

    .read_packet    = yuv4_read_packet,

    .read_seek      = yuv4_read_seek,

};