cmdutils.c

                          AV_SAMPLE_FMT_NONE, GET_SAMPLE_FMT_NAME);
    PRINT_CODEC_SUPPORTED(c, channel_layouts, uint64_t, "channel layouts",
                          0, GET_CH_LAYOUT_DESC);

    if (c->priv_class) {
        show_help_children(c->priv_class,
                           AV_OPT_FLAG_ENCODING_PARAM |
                           AV_OPT_FLAG_DECODING_PARAM);
    }
}

static char get_media_type_char(enum AVMediaType type)
{
    switch (type) {
        case AVMEDIA_TYPE_VIDEO:    return 'V';
        case AVMEDIA_TYPE_AUDIO:    return 'A';
        case AVMEDIA_TYPE_SUBTITLE: return 'S';
        default:                    return '?';
    }
}

static const AVCodec *next_codec_for_id(enum AVCodecID id, const AVCodec *prev,
                                        int encoder)
{
    while ((prev = av_codec_next(prev))) {
        if (prev->id == id &&
            (encoder ? av_codec_is_encoder(prev) : av_codec_is_decoder(prev)))
            return prev;
    }
    return NULL;
}

static void print_codecs_for_id(enum AVCodecID id, int encoder)
{
    const AVCodec *codec = NULL;

    printf(" (%s: ", encoder ? "encoders" : "decoders");

    while ((codec = next_codec_for_id(id, codec, encoder)))
        printf("%s ", codec->name);

    printf(")");
}

int show_codecs(void *optctx, const char *opt, const char *arg)
{
    const AVCodecDescriptor *desc = NULL;

    printf("Codecs:\n"
           " D..... = Decoding supported\n"
           " .E.... = Encoding supported\n"
           " ..V... = Video codec\n"
           " ..A... = Audio codec\n"
           " ..S... = Subtitle codec\n"
           " ...I.. = Intra frame-only codec\n"
           " ....L. = Lossy compression\n"
           " .....S = Lossless compression\n"
           " -------\n");
    while ((desc = avcodec_descriptor_next(desc))) {
        const AVCodec *codec = NULL;

        printf(avcodec_find_decoder(desc->id) ? "D" : ".");
        printf(avcodec_find_encoder(desc->id) ? "E" : ".");

        printf("%c", get_media_type_char(desc->type));
        printf((desc->props & AV_CODEC_PROP_INTRA_ONLY) ? "I" : ".");
        printf((desc->props & AV_CODEC_PROP_LOSSY)      ? "L" : ".");
        printf((desc->props & AV_CODEC_PROP_LOSSLESS)   ? "S" : ".");

        printf(" %-20s %s", desc->name, desc->long_name ? desc->long_name : "");

        /* print decoders/encoders when there's more than one or their
         * names are different from codec name */
        while ((codec = next_codec_for_id(desc->id, codec, 0))) {
            if (strcmp(codec->name, desc->name)) {
                print_codecs_for_id(desc->id, 0);
                break;
            }
        }
        codec = NULL;
        while ((codec = next_codec_for_id(desc->id, codec, 1))) {
            if (strcmp(codec->name, desc->name)) {
                print_codecs_for_id(desc->id, 1);
                break;
            }
        }

        printf("\n");
    }
    return 0;
}

static void print_codecs(int encoder)
{
    const AVCodecDescriptor *desc = NULL;

    printf("%s:\n"
           " V... = Video\n"
           " A... = Audio\n"
           " S... = Subtitle\n"
           " .F.. = Frame-level multithreading\n"
           " ..S. = Slice-level multithreading\n"
           " ...X = Codec is experimental\n"
           " ---\n",
           encoder ? "Encoders" : "Decoders");
    while ((desc = avcodec_descriptor_next(desc))) {
        const AVCodec *codec = NULL;

        while ((codec = next_codec_for_id(desc->id, codec, encoder))) {
            printf("%c", get_media_type_char(desc->type));
            printf((codec->capabilities & CODEC_CAP_FRAME_THREADS) ? "F" : ".");
            printf((codec->capabilities & CODEC_CAP_SLICE_THREADS) ? "S" : ".");
            printf((codec->capabilities & CODEC_CAP_EXPERIMENTAL)  ? "X" : ".");

            printf(" %-20s %s", codec->name, codec->long_name ? codec->long_name : "");
            if (strcmp(codec->name, desc->name))
                printf(" (codec %s)", desc->name);

            printf("\n");
        }
    }
}

int show_decoders(void *optctx, const char *opt, const char *arg)
{
    print_codecs(0);
    return 0;
}

int show_encoders(void *optctx, const char *opt, const char *arg)
{
    print_codecs(1);
    return 0;
}

int show_bsfs(void *optctx, const char *opt, const char *arg)
{
    AVBitStreamFilter *bsf = NULL;

    printf("Bitstream filters:\n");
    while ((bsf = av_bitstream_filter_next(bsf)))
        printf("%s\n", bsf->name);
    printf("\n");
    return 0;
}

int show_protocols(void *optctx, const char *opt, const char *arg)
{
    void *opaque = NULL;
    const char *name;

    printf("Supported file protocols:\n"
           "Input:\n");
    while ((name = avio_enum_protocols(&opaque, 0)))
        printf("%s\n", name);
    printf("Output:\n");
    while ((name = avio_enum_protocols(&opaque, 1)))
        printf("%s\n", name);
    return 0;
}

int show_filters(void *optctx, const char *opt, const char *arg)
{
    const AVFilter av_unused(*filter) = NULL;

    printf("Filters:\n");
#if CONFIG_AVFILTER
    while ((filter = avfilter_next(filter)))
        printf("%-16s %s\n", filter->name, filter->description);
#endif
    return 0;
}

int show_pix_fmts(void *optctx, const char *opt, const char *arg)
{
    const AVPixFmtDescriptor *pix_desc = NULL;

    printf("Pixel formats:\n"
           "I.... = Supported Input  format for conversion\n"
           ".O... = Supported Output format for conversion\n"
           "..H.. = Hardware accelerated format\n"
           "...P. = Paletted format\n"
           "....B = Bitstream format\n"
           "FLAGS NAME            NB_COMPONENTS BITS_PER_PIXEL\n"
           "-----\n");

#if !CONFIG_SWSCALE
#   define sws_isSupportedInput(x)  0
#   define sws_isSupportedOutput(x) 0
#endif

    while ((pix_desc = av_pix_fmt_desc_next(pix_desc))) {
        enum AVPixelFormat pix_fmt = av_pix_fmt_desc_get_id(pix_desc);
        printf("%c%c%c%c%c %-16s       %d            %2d\n",
               sws_isSupportedInput (pix_fmt)              ? 'I' : '.',
               sws_isSupportedOutput(pix_fmt)              ? 'O' : '.',
               pix_desc->flags & AV_PIX_FMT_FLAG_HWACCEL   ? 'H' : '.',
               pix_desc->flags & AV_PIX_FMT_FLAG_PAL       ? 'P' : '.',
               pix_desc->flags & AV_PIX_FMT_FLAG_BITSTREAM ? 'B' : '.',
               pix_desc->name,
               pix_desc->nb_components,
               av_get_bits_per_pixel(pix_desc));
    }
    return 0;
}

int show_sample_fmts(void *optctx, const char *opt, const char *arg)
{
    int i;
    char fmt_str[128];
    for (i = -1; i < AV_SAMPLE_FMT_NB; i++)
        printf("%s\n", av_get_sample_fmt_string(fmt_str, sizeof(fmt_str), i));
    return 0;
}

static void show_help_codec(const char *name, int encoder)
{
    const AVCodecDescriptor *desc;
    const AVCodec *codec;

    if (!name) {
        av_log(NULL, AV_LOG_ERROR, "No codec name specified.\n");
        return;
    }

    codec = encoder ? avcodec_find_encoder_by_name(name) :
                      avcodec_find_decoder_by_name(name);

    if (codec)
        print_codec(codec);
    else if ((desc = avcodec_descriptor_get_by_name(name))) {
        int printed = 0;

        while ((codec = next_codec_for_id(desc->id, codec, encoder))) {
            printed = 1;
            print_codec(codec);
        }

        if (!printed) {
            av_log(NULL, AV_LOG_ERROR, "Codec '%s' is known to Libav, "
                   "but no %s for it are available. Libav might need to be "
                   "recompiled with additional external libraries.\n",
                   name, encoder ? "encoders" : "decoders");
        }
    } else {
        av_log(NULL, AV_LOG_ERROR, "Codec '%s' is not recognized by Libav.\n",
               name);
    }
}

static void show_help_demuxer(const char *name)
{
    const AVInputFormat *fmt = av_find_input_format(name);

    if (!fmt) {
        av_log(NULL, AV_LOG_ERROR, "Unknown format '%s'.\n", name);
        return;
    }

    printf("Demuxer %s [%s]:\n", fmt->name, fmt->long_name);

    if (fmt->extensions)
        printf("    Common extensions: %s.\n", fmt->extensions);

    if (fmt->priv_class)
        show_help_children(fmt->priv_class, AV_OPT_FLAG_DECODING_PARAM);
}

static void show_help_muxer(const char *name)
{
    const AVCodecDescriptor *desc;
    const AVOutputFormat *fmt = av_guess_format(name, NULL, NULL);

    if (!fmt) {
        av_log(NULL, AV_LOG_ERROR, "Unknown format '%s'.\n", name);
        return;
    }

    printf("Muxer %s [%s]:\n", fmt->name, fmt->long_name);

    if (fmt->extensions)
        printf("    Common extensions: %s.\n", fmt->extensions);
    if (fmt->mime_type)
        printf("    Mime type: %s.\n", fmt->mime_type);
    if (fmt->video_codec != AV_CODEC_ID_NONE &&
        (desc = avcodec_descriptor_get(fmt->video_codec))) {
        printf("    Default video codec: %s.\n", desc->name);
    }
    if (fmt->audio_codec != AV_CODEC_ID_NONE &&
        (desc = avcodec_descriptor_get(fmt->audio_codec))) {
        printf("    Default audio codec: %s.\n", desc->name);
    }
    if (fmt->subtitle_codec != AV_CODEC_ID_NONE &&
        (desc = avcodec_descriptor_get(fmt->subtitle_codec))) {
        printf("    Default subtitle codec: %s.\n", desc->name);
    }

    if (fmt->priv_class)
        show_help_children(fmt->priv_class, AV_OPT_FLAG_ENCODING_PARAM);
}

#if CONFIG_AVFILTER
static void show_help_filter(const char *name)
{
    const AVFilter *f = avfilter_get_by_name(name);
    int i, count;

    if (!name) {
        av_log(NULL, AV_LOG_ERROR, "No filter name specified.\n");
        return;
    } else if (!f) {
        av_log(NULL, AV_LOG_ERROR, "Unknown filter '%s'.\n", name);
        return;
    }

    printf("Filter %s [%s]:\n", f->name, f->description);

    if (f->flags & AVFILTER_FLAG_SLICE_THREADS)
        printf("    slice threading supported\n");

    printf("    Inputs:\n");
    count = avfilter_pad_count(f->inputs);
    for (i = 0; i < count; i++) {
        printf("        %d %s (%s)\n", i, avfilter_pad_get_name(f->inputs, i),
               media_type_string(avfilter_pad_get_type(f->inputs, i)));
    }
    if (f->flags & AVFILTER_FLAG_DYNAMIC_INPUTS)
        printf("        dynamic (depending on the options)\n");

    printf("    Outputs:\n");
    count = avfilter_pad_count(f->outputs);
    for (i = 0; i < count; i++) {
        printf("        %d %s (%s)\n", i, avfilter_pad_get_name(f->outputs, i),
               media_type_string(avfilter_pad_get_type(f->outputs, i)));
    }
    if (f->flags & AVFILTER_FLAG_DYNAMIC_OUTPUTS)
        printf("        dynamic (depending on the options)\n");

    if (f->priv_class)
        show_help_children(f->priv_class, AV_OPT_FLAG_VIDEO_PARAM |
                                          AV_OPT_FLAG_AUDIO_PARAM);
}
#endif

int show_help(void *optctx, const char *opt, const char *arg)
{
    char *topic, *par;
    av_log_set_callback(log_callback_help);

    topic = av_strdup(arg ? arg : "");
    par = strchr(topic, '=');
    if (par)
        *par++ = 0;

    if (!*topic) {
        show_help_default(topic, par);
    } else if (!strcmp(topic, "decoder")) {
        show_help_codec(par, 0);
    } else if (!strcmp(topic, "encoder")) {
        show_help_codec(par, 1);
    } else if (!strcmp(topic, "demuxer")) {
        show_help_demuxer(par);
    } else if (!strcmp(topic, "muxer")) {
        show_help_muxer(par);
#if CONFIG_AVFILTER
    } else if (!strcmp(topic, "filter")) {
        show_help_filter(par);
#endif
    } else {
        show_help_default(topic, par);
    }

    av_freep(&topic);
    return 0;
}

int read_yesno(void)
{
    int c = getchar();
    int yesno = (av_toupper(c) == 'Y');

    while (c != '\n' && c != EOF)
        c = getchar();

    return yesno;
}

int cmdutils_read_file(const char *filename, char **bufptr, size_t *size)
{
    int ret;
    FILE *f = fopen(filename, "rb");

    if (!f) {
        av_log(NULL, AV_LOG_ERROR, "Cannot read file '%s': %s\n", filename,
               strerror(errno));
        return AVERROR(errno);
    }
    fseek(f, 0, SEEK_END);
    *size = ftell(f);
    fseek(f, 0, SEEK_SET);
    *bufptr = av_malloc(*size + 1);
    if (!*bufptr) {
        av_log(NULL, AV_LOG_ERROR, "Could not allocate file buffer\n");
        fclose(f);
        return AVERROR(ENOMEM);
    }
    ret = fread(*bufptr, 1, *size, f);
    if (ret < *size) {
        av_free(*bufptr);
        if (ferror(f)) {
            av_log(NULL, AV_LOG_ERROR, "Error while reading file '%s': %s\n",
                   filename, strerror(errno));
            ret = AVERROR(errno);
        } else
            ret = AVERROR_EOF;
    } else {
        ret = 0;
        (*bufptr)[(*size)++] = '\0';
    }

    fclose(f);
    return ret;
}

void init_pts_correction(PtsCorrectionContext *ctx)
{
    ctx->num_faulty_pts = ctx->num_faulty_dts = 0;
    ctx->last_pts = ctx->last_dts = INT64_MIN;
}

int64_t guess_correct_pts(PtsCorrectionContext *ctx, int64_t reordered_pts,
                          int64_t dts)
{
    int64_t pts = AV_NOPTS_VALUE;

    if (dts != AV_NOPTS_VALUE) {
        ctx->num_faulty_dts += dts <= ctx->last_dts;
        ctx->last_dts = dts;
    }
    if (reordered_pts != AV_NOPTS_VALUE) {
        ctx->num_faulty_pts += reordered_pts <= ctx->last_pts;
        ctx->last_pts = reordered_pts;
    }
    if ((ctx->num_faulty_pts<=ctx->num_faulty_dts || dts == AV_NOPTS_VALUE)
        && reordered_pts != AV_NOPTS_VALUE)
        pts = reordered_pts;
    else
        pts = dts;

    return pts;
}

FILE *get_preset_file(char *filename, size_t filename_size,
                      const char *preset_name, int is_path,
                      const char *codec_name)
{
    FILE *f = NULL;
    int i;
    const char *base[3] = { getenv("AVCONV_DATADIR"),
                            getenv("HOME"),
                            AVCONV_DATADIR, };

    if (is_path) {
        av_strlcpy(filename, preset_name, filename_size);
        f = fopen(filename, "r");
    } else {
        for (i = 0; i < 3 && !f; i++) {
            if (!base[i])
                continue;
            snprintf(filename, filename_size, "%s%s/%s.avpreset", base[i],
                     i != 1 ? "" : "/.avconv", preset_name);
            f = fopen(filename, "r");
            if (!f && codec_name) {
                snprintf(filename, filename_size,
                         "%s%s/%s-%s.avpreset",
                         base[i], i != 1 ? "" : "/.avconv", codec_name,
                         preset_name);
                f = fopen(filename, "r");
            }
        }
    }

    return f;
}

int check_stream_specifier(AVFormatContext *s, AVStream *st, const char *spec)
{
    if (*spec <= '9' && *spec >= '0') /* opt:index */
        return strtol(spec, NULL, 0) == st->index;
    else if (*spec == 'v' || *spec == 'a' || *spec == 's' || *spec == 'd' ||
             *spec == 't') { /* opt:[vasdt] */
        enum AVMediaType type;

        switch (*spec++) {
        case 'v': type = AVMEDIA_TYPE_VIDEO;      break;
        case 'a': type = AVMEDIA_TYPE_AUDIO;      break;
        case 's': type = AVMEDIA_TYPE_SUBTITLE;   break;
        case 'd': type = AVMEDIA_TYPE_DATA;       break;
        case 't': type = AVMEDIA_TYPE_ATTACHMENT; break;
        default:  av_assert0(0);
        }
        if (type != st->codec->codec_type)
            return 0;
        if (*spec++ == ':') { /* possibly followed by :index */
            int i, index = strtol(spec, NULL, 0);
            for (i = 0; i < s->nb_streams; i++)
                if (s->streams[i]->codec->codec_type == type && index-- == 0)
                   return i == st->index;
            return 0;
        }
        return 1;
    } else if (*spec == 'p' && *(spec + 1) == ':') {
        int prog_id, i, j;
        char *endptr;
        spec += 2;
        prog_id = strtol(spec, &endptr, 0);
        for (i = 0; i < s->nb_programs; i++) {
            if (s->programs[i]->id != prog_id)
                continue;

            if (*endptr++ == ':') {
                int stream_idx = strtol(endptr, NULL, 0);
                return stream_idx >= 0 &&
                    stream_idx < s->programs[i]->nb_stream_indexes &&
                    st->index == s->programs[i]->stream_index[stream_idx];
            }

            for (j = 0; j < s->programs[i]->nb_stream_indexes; j++)
                if (st->index == s->programs[i]->stream_index[j])
                    return 1;
        }
        return 0;
    } else if (*spec == 'i' && *(spec + 1) == ':') {
        int stream_id;
        char *endptr;
        spec += 2;
        stream_id = strtol(spec, &endptr, 0);
        return stream_id == st->id;
    } else if (!*spec) /* empty specifier, matches everything */
        return 1;

    av_log(s, AV_LOG_ERROR, "Invalid stream specifier: %s.\n", spec);
    return AVERROR(EINVAL);
}

AVDictionary *filter_codec_opts(AVDictionary *opts, enum AVCodecID codec_id,
                                AVFormatContext *s, AVStream *st, AVCodec *codec)
{
    AVDictionary    *ret = NULL;
    AVDictionaryEntry *t = NULL;
    int            flags = s->oformat ? AV_OPT_FLAG_ENCODING_PARAM
                                      : AV_OPT_FLAG_DECODING_PARAM;
    char          prefix = 0;
    const AVClass    *cc = avcodec_get_class();

    if (!codec)
        codec            = s->oformat ? avcodec_find_encoder(codec_id)
                                      : avcodec_find_decoder(codec_id);

    switch (st->codec->codec_type) {
    case AVMEDIA_TYPE_VIDEO:
        prefix  = 'v';
        flags  |= AV_OPT_FLAG_VIDEO_PARAM;
        break;
    case AVMEDIA_TYPE_AUDIO:
        prefix  = 'a';
        flags  |= AV_OPT_FLAG_AUDIO_PARAM;
        break;
    case AVMEDIA_TYPE_SUBTITLE:
        prefix  = 's';
        flags  |= AV_OPT_FLAG_SUBTITLE_PARAM;
        break;
    }

    while (t = av_dict_get(opts, "", t, AV_DICT_IGNORE_SUFFIX)) {
        char *p = strchr(t->key, ':');

        /* check stream specification in opt name */
        if (p)
            switch (check_stream_specifier(s, st, p + 1)) {
            case  1: *p = 0; break;
            case  0:         continue;
            default:         return NULL;
            }

        if (av_opt_find(&cc, t->key, NULL, flags, AV_OPT_SEARCH_FAKE_OBJ) ||
            (codec && codec->priv_class &&
             av_opt_find(&codec->priv_class, t->key, NULL, flags,
                         AV_OPT_SEARCH_FAKE_OBJ)))
            av_dict_set(&ret, t->key, t->value, 0);
        else if (t->key[0] == prefix &&
                 av_opt_find(&cc, t->key + 1, NULL, flags,
                             AV_OPT_SEARCH_FAKE_OBJ))
            av_dict_set(&ret, t->key + 1, t->value, 0);

        if (p)
            *p = ':';
    }
    return ret;
}

AVDictionary **setup_find_stream_info_opts(AVFormatContext *s,
                                           AVDictionary *codec_opts)
{
    int i;
    AVDictionary **opts;

    if (!s->nb_streams)
        return NULL;
    opts = av_mallocz(s->nb_streams * sizeof(*opts));
    if (!opts) {
        av_log(NULL, AV_LOG_ERROR,
               "Could not alloc memory for stream options.\n");
        return NULL;
    }
    for (i = 0; i < s->nb_streams; i++)
        opts[i] = filter_codec_opts(codec_opts, s->streams[i]->codec->codec_id,
                                    s, s->streams[i], NULL);
    return opts;
}

void *grow_array(void *array, int elem_size, int *size, int new_size)
{
    if (new_size >= INT_MAX / elem_size) {
        av_log(NULL, AV_LOG_ERROR, "Array too big.\n");
        exit_program(1);
    }
    if (*size < new_size) {
        uint8_t *tmp = av_realloc(array, new_size*elem_size);
        if (!tmp) {
            av_log(NULL, AV_LOG_ERROR, "Could not alloc buffer.\n");
            exit_program(1);
        }
        memset(tmp + *size*elem_size, 0, (new_size-*size) * elem_size);
        *size = new_size;
        return tmp;
    }
    return array;
}

const char *media_type_string(enum AVMediaType media_type)
{
    switch (media_type) {
    case AVMEDIA_TYPE_VIDEO:      return "video";
    case AVMEDIA_TYPE_AUDIO:      return "audio";
    case AVMEDIA_TYPE_DATA:       return "data";
    case AVMEDIA_TYPE_SUBTITLE:   return "subtitle";
    case AVMEDIA_TYPE_ATTACHMENT: return "attachment";
    default:                      return "unknown";
    }
}