/* * 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 "libavutil/avstring.h"#include "libavutil/bprint.h"#include "libavutil/opt.h"#include "libavutil/thread.h" #include "avio_internal.h"#include "avformat.h"#include "id3v2.h"#include "internal.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;} ff_const59 AVOutputFormat *av_guess_format(const char *short_name, const char *filename,                                const char *mime_type){    const AVOutputFormat *fmt = NULL;    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))) {        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 = (AVOutputFormat*)fmt;        }    }    return fmt_found;} enum AVCodecID av_guess_codec(ff_const59 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)) {        ff_const59 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        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 if (type == AVMEDIA_TYPE_DATA)        return fmt->data_codec;    else        return AV_CODEC_ID_NONE;} ff_const59 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 (AVInputFormat*)fmt;    return NULL;} ff_const59 AVInputFormat *av_probe_input_format3(ff_const59 AVProbeData *pd, int is_opened,                                      int *score_ret){    AVProbeData lpd = *pd;    const AVInputFormat *fmt1 = NULL;    ff_const59 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;     if (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;        } else            nodat = ID3_GREATER_PROBE;    }     while ((fmt1 = av_demuxer_iterate(&i))) {        if (!is_opened == !(fmt1->flags & AVFMT_NOFILE) && strcmp(fmt1->name, "image2"))            continue;        score = 0;        if (fmt1->read_probe) {            score = fmt1->read_probe(&lpd);            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)) {            if (AVPROBE_SCORE_MIME > score) {                av_log(NULL, AV_LOG_DEBUG, "Probing %s score:%d increased to %d due to MIME type\n", fmt1->name, score, AVPROBE_SCORE_MIME);                score = AVPROBE_SCORE_MIME;            }        }        if (score > score_max) {            score_max = score;            fmt       = (AVInputFormat*)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;} ff_const59 AVInputFormat *av_probe_input_format2(ff_const59 AVProbeData *pd, int is_opened, int *score_max){    int score_ret;    ff_const59 AVInputFormat *fmt = av_probe_input_format3(pd, is_opened, &score_ret);    if (score_ret > *score_max) {        *score_max = score_ret;        return fmt;    } else        return NULL;} ff_const59 AVInputFormat *av_probe_input_format(ff_const59 AVProbeData *pd, int is_opened){    int score = 0;    return av_probe_input_format2(pd, is_opened, &score);} int av_probe_input_buffer2(AVIOContext *pb, ff_const59 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;     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(pd.mime_type, ';') : NULL;        if (semi) {            *semi = '\0';        }    }     for (probe_size = PROBE_BUF_MIN; probe_size <= max_probe_size && !*fmt;         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 */        }        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. */        *fmt = av_probe_input_format2(&pd, 1, &score);        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, ff_const59 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;}