/*

 * Format register and lookup

 * Copyright (c) 2000, 2001, 2002 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 "config_components.h"

#include "libavutil/avstring.h"

#include "libavutil/mem.h"

#include "libavutil/opt.h"

#include "avio_internal.h"

#include "avformat.h"

#include "demux.h"

#include "id3v2.h"

#include "internal.h"

#include "url.h"

/**

 * @file

 * Format register and lookup

 */

int av_match_ext(const char *filename, const char *extensions)

{

    const char *ext;

    if (!filename)

        return 0;

    ext = strrchr(filename, '.');

    if (ext)

        return av_match_name(ext + 1, extensions);

    return 0;

}

int ff_match_url_ext(const char *url, const char *extensions)

{

    const char *ext;

    URLComponents uc;

    int ret;

    char scratchpad[128];

    if (!url)

        return 0;

    ret = ff_url_decompose(&uc, url, NULL);

    if (ret < 0 || !URL_COMPONENT_HAVE(uc, scheme))

        return ret;

    for (ext = uc.query; *ext != '.' && ext > uc.path; ext--)

        ;

    if (*ext != '.')

        return 0;

    if (uc.query - ext > sizeof(scratchpad))

        return AVERROR(ENOMEM); //not enough memory in our scratchpad

    av_strlcpy(scratchpad, ext + 1, uc.query - ext);

    return av_match_name(scratchpad, extensions);

}

const AVOutputFormat *av_guess_format(const char *short_name, const char *filename,

                                      const char *mime_type)

{

    const AVOutputFormat *fmt = NULL;

    const AVOutputFormat *fmt_found = NULL;

    void *i = 0;

    int score_max, score;

    /* specific test for image sequences */

#if CONFIG_IMAGE2_MUXER

    if (!short_name && filename &&

        av_filename_number_test(filename) &&

        ff_guess_image2_codec(filename) != AV_CODEC_ID_NONE) {

        return av_guess_format("image2", NULL, NULL);

    }

#endif

    /* Find the proper file type. */

    score_max = 0;

    while ((fmt = av_muxer_iterate(&i))) {

        if (fmt->flags & AVFMT_EXPERIMENTAL && !short_name)

            continue;

        score = 0;

        if (fmt->name && short_name && av_match_name(short_name, fmt->name))

            score += 100;

        if (fmt->mime_type && mime_type && !strcmp(fmt->mime_type, mime_type))

            score += 10;

        if (filename && fmt->extensions &&

            av_match_ext(filename, fmt->extensions)) {

            score += 5;

        }

        if (score > score_max) {

            score_max = score;

            fmt_found = fmt;

        }

    }

    return fmt_found;

}

enum AVCodecID av_guess_codec(const AVOutputFormat *fmt, const char *short_name,

                              const char *filename, const char *mime_type,

                              enum AVMediaType type)

{

    if (av_match_name("segment", fmt->name) || av_match_name("ssegment", fmt->name)) {

        const AVOutputFormat *fmt2 = av_guess_format(NULL, filename, NULL);

        if (fmt2)

            fmt = fmt2;

    }

    if (type == AVMEDIA_TYPE_VIDEO) {

        enum AVCodecID codec_id = AV_CODEC_ID_NONE;

#if CONFIG_IMAGE2_MUXER || CONFIG_IMAGE2PIPE_MUXER

        if (!strcmp(fmt->name, "image2") || !strcmp(fmt->name, "image2pipe")) {

            codec_id = ff_guess_image2_codec(filename);

        }

#endif

        if (codec_id == AV_CODEC_ID_NONE)

            codec_id = fmt->video_codec;

        return codec_id;

    } else if (type == AVMEDIA_TYPE_AUDIO)

        return fmt->audio_codec;

    else if (type == AVMEDIA_TYPE_SUBTITLE)

        return fmt->subtitle_codec;

    else

        return AV_CODEC_ID_NONE;

}

const AVInputFormat *av_find_input_format(const char *short_name)

{

    const AVInputFormat *fmt = NULL;

    void *i = 0;

    while ((fmt = av_demuxer_iterate(&i)))

        if (av_match_name(short_name, fmt->name))

            return fmt;

    return NULL;

}

static const AVInputFormat *

probe_input_format_internal(const AVProbeData *pd, int is_opened,

                            int *score_ret, int *undecided)

{

    AVProbeData lpd = *pd;

    const AVInputFormat *fmt1 = NULL;

    const AVInputFormat *fmt = NULL;

    int score, score_max = 0;

    void *i = 0;

    const static uint8_t zerobuffer[AVPROBE_PADDING_SIZE];

    enum nodat {

        NO_ID3,

        ID3_ALMOST_GREATER_PROBE,

        ID3_GREATER_PROBE,

        ID3_GREATER_MAX_PROBE,

    } nodat = NO_ID3;

    if (!lpd.buf)

        lpd.buf = (unsigned char *) zerobuffer;

    while (lpd.buf_size > 10 && ff_id3v2_match(lpd.buf, ID3v2_DEFAULT_MAGIC)) {

        int id3len = ff_id3v2_tag_len(lpd.buf);

        if (lpd.buf_size > id3len + 16) {

            if (lpd.buf_size < 2LL*id3len + 16)

                nodat = ID3_ALMOST_GREATER_PROBE;

            lpd.buf      += id3len;

            lpd.buf_size -= id3len;

        } else if (id3len >= PROBE_BUF_MAX) {

            nodat = ID3_GREATER_MAX_PROBE;

            break;

        } else {

            nodat = ID3_GREATER_PROBE;

            break;

        }

    }

    while ((fmt1 = av_demuxer_iterate(&i))) {

        if (fmt1->flags & AVFMT_EXPERIMENTAL)

            continue;

        if (!is_opened == !(fmt1->flags & AVFMT_NOFILE) && strcmp(fmt1->name, "image2"))

            continue;

        score = 0;

        if (ffifmt(fmt1)->read_probe) {

            score = ffifmt(fmt1)->read_probe(&lpd);

            if (score == AVERROR(EAGAIN)) {

                av_log(NULL, AV_LOG_TRACE, "Probing %s score:undecided size:%d\n",

                       fmt1->name, lpd.buf_size);

                if (undecided)

                    *undecided = 1;

                score = 0;

            } else if (score)

                av_log(NULL, AV_LOG_TRACE, "Probing %s score:%d size:%d\n", fmt1->name, score, lpd.buf_size);

            if (fmt1->extensions && av_match_ext(lpd.filename, fmt1->extensions)) {

                switch (nodat) {

                case NO_ID3:

                    score = FFMAX(score, 1);

                    break;

                case ID3_GREATER_PROBE:

                case ID3_ALMOST_GREATER_PROBE:

                    score = FFMAX(score, AVPROBE_SCORE_EXTENSION / 2 - 1);

                    break;

                case ID3_GREATER_MAX_PROBE:

                    score = FFMAX(score, AVPROBE_SCORE_EXTENSION);

                    break;

                }

            }

        } else if (fmt1->extensions) {

            if (av_match_ext(lpd.filename, fmt1->extensions))

                score = AVPROBE_SCORE_EXTENSION;

        }

        if (av_match_name(lpd.mime_type, fmt1->mime_type)) {

            int old_score = score;

            score += AVPROBE_SCORE_MIME_BONUS;

            if (score > AVPROBE_SCORE_MAX) score = AVPROBE_SCORE_MAX;

            av_log(NULL, AV_LOG_DEBUG, "Probing %s score:%d increased to %d due to MIME type\n", fmt1->name, old_score, score);

        }

        if (score > score_max) {

            score_max = score;

            fmt       = fmt1;

        } else if (score == score_max)

            fmt = NULL;

    }

    if (nodat == ID3_GREATER_PROBE)

        score_max = FFMIN(AVPROBE_SCORE_EXTENSION / 2 - 1, score_max);

    *score_ret = score_max;

    return fmt;

}

const AVInputFormat *av_probe_input_format3(const AVProbeData *pd,

                                            int is_opened, int *score_ret)

{

    return probe_input_format_internal(pd, is_opened, score_ret, NULL);

}

const AVInputFormat *av_probe_input_format2(const AVProbeData *pd,

                                            int is_opened, int *score_max)

{

    int score_ret;

    const AVInputFormat *fmt;

    fmt = probe_input_format_internal(pd, is_opened, &score_ret, NULL);

    if (score_ret > *score_max) {

        *score_max = score_ret;

        return fmt;

    } else

        return NULL;

}

const AVInputFormat *av_probe_input_format(const AVProbeData *pd, int is_opened)

{

    int score = 0;

    return probe_input_format_internal(pd, is_opened, &score, NULL);

}

int av_probe_input_buffer2(AVIOContext *pb, const AVInputFormat **fmt,

                           const char *filename, void *logctx,

                           unsigned int offset, unsigned int max_probe_size)

{

    AVProbeData pd = { filename ? filename : "" };

    uint8_t *buf = NULL;

    int ret = 0, probe_size, buf_offset = 0;

    int score = 0;

    int ret2;

    int eof = 0;

    if (!max_probe_size)

        max_probe_size = PROBE_BUF_MAX;

    else if (max_probe_size < PROBE_BUF_MIN) {

        av_log(logctx, AV_LOG_ERROR,

               "Specified probe size value %u cannot be < %u\n", max_probe_size, PROBE_BUF_MIN);

        return AVERROR(EINVAL);

    }

    if (offset >= max_probe_size)

        return AVERROR(EINVAL);

    if (pb->av_class) {

        uint8_t *mime_type_opt = NULL;

        char *semi;

        av_opt_get(pb, "mime_type", AV_OPT_SEARCH_CHILDREN, &mime_type_opt);

        pd.mime_type = (const char *)mime_type_opt;

        semi = pd.mime_type ? strchr(mime_type_opt, ';') : NULL;

        if (semi) {

            *semi = '\0';

        }

    }

    for (probe_size = PROBE_BUF_MIN; probe_size <= max_probe_size && !*fmt && !eof;

         probe_size = FFMIN(probe_size << 1,

                            FFMAX(max_probe_size, probe_size + 1))) {

        score = probe_size < max_probe_size ? AVPROBE_SCORE_RETRY : 0;

        /* Read probe data. */

        if ((ret = av_reallocp(&buf, probe_size + AVPROBE_PADDING_SIZE)) < 0)

            goto fail;

        if ((ret = avio_read(pb, buf + buf_offset,

                             probe_size - buf_offset)) < 0) {

            /* Fail if error was not end of file, otherwise, lower score. */

            if (ret != AVERROR_EOF)

                goto fail;

            score = 0;

            ret   = 0;          /* error was end of file, nothing read */

            eof   = 1;

        }

        buf_offset += ret;

        if (buf_offset < offset)

            continue;

        pd.buf_size = buf_offset - offset;

        pd.buf = &buf[offset];

        memset(pd.buf + pd.buf_size, 0, AVPROBE_PADDING_SIZE);

        /* Guess file format. */

        int score_new, undecided = 0;

        const AVInputFormat *fmt_new;

        fmt_new = probe_input_format_internal(&pd, 1, &score_new, &undecided);

        /* Retry undecided formats as long as we have more data to feed */

        if (undecided && probe_size < max_probe_size && !eof) {

            continue;

        } else if (score_new > score) {

            score = score_new;

            *fmt  = fmt_new;

        }

        if (*fmt) {

            /* This can only be true in the last iteration. */

            if (score <= AVPROBE_SCORE_RETRY) {

                av_log(logctx, AV_LOG_WARNING,

                       "Format %s detected only with low score of %d, "

                       "misdetection possible!\n", (*fmt)->name, score);

            } else

                av_log(logctx, AV_LOG_DEBUG,

                       "Format %s probed with size=%d and score=%d\n",

                       (*fmt)->name, probe_size, score);

#if 0

            FILE *f = fopen("probestat.tmp", "ab");

            fprintf(f, "probe_size:%d format:%s score:%d filename:%s\n", probe_size, (*fmt)->name, score, filename);

            fclose(f);

#endif

        }

    }

    if (!*fmt)

        ret = AVERROR_INVALIDDATA;

fail:

    /* Rewind. Reuse probe buffer to avoid seeking. */

    ret2 = ffio_rewind_with_probe_data(pb, &buf, buf_offset);

    if (ret >= 0)

        ret = ret2;

    av_freep(&pd.mime_type);

    return ret < 0 ? ret : score;

}

int av_probe_input_buffer(AVIOContext *pb, const AVInputFormat **fmt,

                          const char *filename, void *logctx,

                          unsigned int offset, unsigned int max_probe_size)

{

    int ret = av_probe_input_buffer2(pb, fmt, filename, logctx, offset, max_probe_size);

    return ret < 0 ? ret : 0;

}