ffprobe.c

    {"nk",       "force no key printing", OFFSET(nokey),           AV_OPT_TYPE_INT,    {.i64=1},    0,        1        },
    {"escape",   "set escape mode",       OFFSET(escape_mode_str), AV_OPT_TYPE_STRING, {.str="csv"}, CHAR_MIN, CHAR_MAX },
    {"e",        "set escape mode",       OFFSET(escape_mode_str), AV_OPT_TYPE_STRING, {.str="csv"}, CHAR_MIN, CHAR_MAX },
    {"print_section", "print section name", OFFSET(print_section), AV_OPT_TYPE_INT,    {.i64=1},    0,        1        },
    {"p",             "print section name", OFFSET(print_section), AV_OPT_TYPE_INT,    {.i64=1},    0,        1        },
    {NULL},
};

DEFINE_WRITER_CLASS(csv);

static const Writer csv_writer = {
    .name                 = "csv",
    .priv_size            = sizeof(CompactContext),
    .init                 = compact_init,
    .print_section_header = compact_print_section_header,
    .print_section_footer = compact_print_section_footer,
    .print_integer        = compact_print_int,
    .print_string         = compact_print_str,
    .flags = WRITER_FLAG_DISPLAY_OPTIONAL_FIELDS,
    .priv_class           = &csv_class,
};

/* Flat output */

typedef struct FlatContext {
    const AVClass *class;
    const char *sep_str;
    char sep;
    int hierarchical;
} FlatContext;

#undef OFFSET
#define OFFSET(x) offsetof(FlatContext, x)

static const AVOption flat_options[]= {
    {"sep_char", "set separator",    OFFSET(sep_str),    AV_OPT_TYPE_STRING, {.str="."},  CHAR_MIN, CHAR_MAX },
    {"s",        "set separator",    OFFSET(sep_str),    AV_OPT_TYPE_STRING, {.str="."},  CHAR_MIN, CHAR_MAX },
    {"hierarchical", "specify if the section specification should be hierarchical", OFFSET(hierarchical), AV_OPT_TYPE_INT, {.i64=1}, 0, 1 },
    {"h",           "specify if the section specification should be hierarchical", OFFSET(hierarchical), AV_OPT_TYPE_INT, {.i64=1}, 0, 1 },
    {NULL},
};

DEFINE_WRITER_CLASS(flat);

static av_cold int flat_init(WriterContext *wctx)
{
    FlatContext *flat = wctx->priv;

    if (strlen(flat->sep_str) != 1) {
        av_log(wctx, AV_LOG_ERROR, "Item separator '%s' specified, but must contain a single character\n",
               flat->sep_str);
        return AVERROR(EINVAL);
    }
    flat->sep = flat->sep_str[0];

    return 0;
}

static const char *flat_escape_key_str(AVBPrint *dst, const char *src, const char sep)
{
    const char *p;

    for (p = src; *p; p++) {
        if (!((*p >= '0' && *p <= '9') ||
              (*p >= 'a' && *p <= 'z') ||
              (*p >= 'A' && *p <= 'Z')))
            av_bprint_chars(dst, '_', 1);
        else
            av_bprint_chars(dst, *p, 1);
    }
    return dst->str;
}

static const char *flat_escape_value_str(AVBPrint *dst, const char *src)
{
    const char *p;

    for (p = src; *p; p++) {
        switch (*p) {
        case '\n': av_bprintf(dst, "%s", "\\n");  break;
        case '\r': av_bprintf(dst, "%s", "\\r");  break;
        case '\\': av_bprintf(dst, "%s", "\\\\"); break;
        case '"':  av_bprintf(dst, "%s", "\\\""); break;
        case '`':  av_bprintf(dst, "%s", "\\`");  break;
        case '$':  av_bprintf(dst, "%s", "\\$");  break;
        default:   av_bprint_chars(dst, *p, 1);   break;
        }
    }
    return dst->str;
}

static void flat_print_section_header(WriterContext *wctx)
{
    FlatContext *flat = wctx->priv;
    AVBPrint *buf = &wctx->section_pbuf[wctx->level];
    const struct section *section = wctx->section[wctx->level];
    const struct section *parent_section = wctx->level ?
        wctx->section[wctx->level-1] : NULL;

    /* build section header */
    av_bprint_clear(buf);
    if (!parent_section)
        return;
    av_bprintf(buf, "%s", wctx->section_pbuf[wctx->level-1].str);

    if (flat->hierarchical ||
        !(section->flags & (SECTION_FLAG_IS_ARRAY|SECTION_FLAG_IS_WRAPPER))) {
        av_bprintf(buf, "%s%s", wctx->section[wctx->level]->name, flat->sep_str);

        if (parent_section->flags & SECTION_FLAG_IS_ARRAY) {
            int n = parent_section->id == SECTION_ID_PACKETS_AND_FRAMES ?
                wctx->nb_section_packet_frame : wctx->nb_item[wctx->level-1];
            av_bprintf(buf, "%d%s", n, flat->sep_str);
        }
    }
}

static void flat_print_int(WriterContext *wctx, const char *key, long long int value)
{
    printf("%s%s=%lld\n", wctx->section_pbuf[wctx->level].str, key, value);
}

static void flat_print_str(WriterContext *wctx, const char *key, const char *value)
{
    FlatContext *flat = wctx->priv;
    AVBPrint buf;

    printf("%s", wctx->section_pbuf[wctx->level].str);
    av_bprint_init(&buf, 1, AV_BPRINT_SIZE_UNLIMITED);
    printf("%s=", flat_escape_key_str(&buf, key, flat->sep));
    av_bprint_clear(&buf);
    printf("\"%s\"\n", flat_escape_value_str(&buf, value));
    av_bprint_finalize(&buf, NULL);
}

static const Writer flat_writer = {
    .name                  = "flat",
    .priv_size             = sizeof(FlatContext),
    .init                  = flat_init,
    .print_section_header  = flat_print_section_header,
    .print_integer         = flat_print_int,
    .print_string          = flat_print_str,
    .flags = WRITER_FLAG_DISPLAY_OPTIONAL_FIELDS|WRITER_FLAG_PUT_PACKETS_AND_FRAMES_IN_SAME_CHAPTER,
    .priv_class            = &flat_class,
};

/* INI format output */

typedef struct {
    const AVClass *class;
    int hierarchical;
} INIContext;

#undef OFFSET
#define OFFSET(x) offsetof(INIContext, x)

static const AVOption ini_options[] = {
    {"hierarchical", "specify if the section specification should be hierarchical", OFFSET(hierarchical), AV_OPT_TYPE_INT, {.i64=1}, 0, 1 },
    {"h",           "specify if the section specification should be hierarchical", OFFSET(hierarchical), AV_OPT_TYPE_INT, {.i64=1}, 0, 1 },
    {NULL},
};

DEFINE_WRITER_CLASS(ini);

static char *ini_escape_str(AVBPrint *dst, const char *src)
{
    int i = 0;
    char c = 0;

    while (c = src[i++]) {
        switch (c) {
        case '\b': av_bprintf(dst, "%s", "\\b"); break;
        case '\f': av_bprintf(dst, "%s", "\\f"); break;
        case '\n': av_bprintf(dst, "%s", "\\n"); break;
        case '\r': av_bprintf(dst, "%s", "\\r"); break;
        case '\t': av_bprintf(dst, "%s", "\\t"); break;
        case '\\':
        case '#' :
        case '=' :
        case ':' : av_bprint_chars(dst, '\\', 1);
        default:
            if ((unsigned char)c < 32)
                av_bprintf(dst, "\\x00%02x", c & 0xff);
            else
                av_bprint_chars(dst, c, 1);
            break;
        }
    }
    return dst->str;
}

static void ini_print_section_header(WriterContext *wctx)
{
    INIContext *ini = wctx->priv;
    AVBPrint *buf = &wctx->section_pbuf[wctx->level];
    const struct section *section = wctx->section[wctx->level];
    const struct section *parent_section = wctx->level ?
        wctx->section[wctx->level-1] : NULL;

    av_bprint_clear(buf);
    if (!parent_section) {
        printf("# ffprobe output\n\n");
        return;
    }

    if (wctx->nb_item[wctx->level-1])
        printf("\n");

    av_bprintf(buf, "%s", wctx->section_pbuf[wctx->level-1].str);
    if (ini->hierarchical ||
        !(section->flags & (SECTION_FLAG_IS_ARRAY|SECTION_FLAG_IS_WRAPPER))) {
        av_bprintf(buf, "%s%s", buf->str[0] ? "." : "", wctx->section[wctx->level]->name);

        if (parent_section->flags & SECTION_FLAG_IS_ARRAY) {
            int n = parent_section->id == SECTION_ID_PACKETS_AND_FRAMES ?
                wctx->nb_section_packet_frame : wctx->nb_item[wctx->level-1];
            av_bprintf(buf, ".%d", n);
        }
    }

    if (!(section->flags & (SECTION_FLAG_IS_ARRAY|SECTION_FLAG_IS_WRAPPER)))
        printf("[%s]\n", buf->str);
}

static void ini_print_str(WriterContext *wctx, const char *key, const char *value)
{
    AVBPrint buf;

    av_bprint_init(&buf, 1, AV_BPRINT_SIZE_UNLIMITED);
    printf("%s=", ini_escape_str(&buf, key));
    av_bprint_clear(&buf);
    printf("%s\n", ini_escape_str(&buf, value));
    av_bprint_finalize(&buf, NULL);
}

static void ini_print_int(WriterContext *wctx, const char *key, long long int value)
{
    printf("%s=%lld\n", key, value);
}

static const Writer ini_writer = {
    .name                  = "ini",
    .priv_size             = sizeof(INIContext),
    .print_section_header  = ini_print_section_header,
    .print_integer         = ini_print_int,
    .print_string          = ini_print_str,
    .flags = WRITER_FLAG_DISPLAY_OPTIONAL_FIELDS|WRITER_FLAG_PUT_PACKETS_AND_FRAMES_IN_SAME_CHAPTER,
    .priv_class            = &ini_class,
};

/* JSON output */

typedef struct {
    const AVClass *class;
    int indent_level;
    int compact;
    const char *item_sep, *item_start_end;
} JSONContext;

#undef OFFSET
#define OFFSET(x) offsetof(JSONContext, x)

static const AVOption json_options[]= {
    { "compact", "enable compact output", OFFSET(compact), AV_OPT_TYPE_INT, {.i64=0}, 0, 1 },
    { "c",       "enable compact output", OFFSET(compact), AV_OPT_TYPE_INT, {.i64=0}, 0, 1 },
    { NULL }
};

DEFINE_WRITER_CLASS(json);

static av_cold int json_init(WriterContext *wctx)
{
    JSONContext *json = wctx->priv;

    json->item_sep       = json->compact ? ", " : ",\n";
    json->item_start_end = json->compact ? " "  : "\n";

    return 0;
}

static const char *json_escape_str(AVBPrint *dst, const char *src, void *log_ctx)
{
    static const char json_escape[] = {'"', '\\', '\b', '\f', '\n', '\r', '\t', 0};
    static const char json_subst[]  = {'"', '\\',  'b',  'f',  'n',  'r',  't', 0};
    const char *p;

    for (p = src; *p; p++) {
        char *s = strchr(json_escape, *p);
        if (s) {
            av_bprint_chars(dst, '\\', 1);
            av_bprint_chars(dst, json_subst[s - json_escape], 1);
        } else if ((unsigned char)*p < 32) {
            av_bprintf(dst, "\\u00%02x", *p & 0xff);
        } else {
            av_bprint_chars(dst, *p, 1);
        }
    }
    return dst->str;
}

#define JSON_INDENT() printf("%*c", json->indent_level * 4, ' ')

static void json_print_section_header(WriterContext *wctx)
{
    JSONContext *json = wctx->priv;
    AVBPrint buf;
    const struct section *section = wctx->section[wctx->level];
    const struct section *parent_section = wctx->level ?
        wctx->section[wctx->level-1] : NULL;

    if (wctx->level && wctx->nb_item[wctx->level-1])
        printf(",\n");

    if (section->flags & SECTION_FLAG_IS_WRAPPER) {
        printf("{\n");
        json->indent_level++;
    } else {
        av_bprint_init(&buf, 1, AV_BPRINT_SIZE_UNLIMITED);
        json_escape_str(&buf, section->name, wctx);
        JSON_INDENT();

        json->indent_level++;
        if (section->flags & SECTION_FLAG_IS_ARRAY) {
            printf("\"%s\": [\n", buf.str);
        } else if (parent_section && !(parent_section->flags & SECTION_FLAG_IS_ARRAY)) {
            printf("\"%s\": {%s", buf.str, json->item_start_end);
        } else {
            printf("{%s", json->item_start_end);

            /* this is required so the parser can distinguish between packets and frames */
            if (parent_section && parent_section->id == SECTION_ID_PACKETS_AND_FRAMES) {
                if (!json->compact)
                    JSON_INDENT();
                printf("\"type\": \"%s\"%s", section->name, json->item_sep);
            }
        }
        av_bprint_finalize(&buf, NULL);
    }
}

static void json_print_section_footer(WriterContext *wctx)
{
    JSONContext *json = wctx->priv;
    const struct section *section = wctx->section[wctx->level];

    if (wctx->level == 0) {
        json->indent_level--;
        printf("\n}\n");
    } else if (section->flags & SECTION_FLAG_IS_ARRAY) {
        printf("\n");
        json->indent_level--;
        JSON_INDENT();
        printf("]");
    } else {
        printf("%s", json->item_start_end);
        json->indent_level--;
        if (!json->compact)
            JSON_INDENT();
        printf("}");
    }
}

static inline void json_print_item_str(WriterContext *wctx,
                                       const char *key, const char *value)
{
    AVBPrint buf;

    av_bprint_init(&buf, 1, AV_BPRINT_SIZE_UNLIMITED);
    printf("\"%s\":", json_escape_str(&buf, key,   wctx));
    av_bprint_clear(&buf);
    printf(" \"%s\"", json_escape_str(&buf, value, wctx));
    av_bprint_finalize(&buf, NULL);
}

static void json_print_str(WriterContext *wctx, const char *key, const char *value)
{
    JSONContext *json = wctx->priv;

    if (wctx->nb_item[wctx->level])
        printf("%s", json->item_sep);
    if (!json->compact)
        JSON_INDENT();
    json_print_item_str(wctx, key, value);
}

static void json_print_int(WriterContext *wctx, const char *key, long long int value)
{
    JSONContext *json = wctx->priv;
    AVBPrint buf;

    if (wctx->nb_item[wctx->level])
        printf("%s", json->item_sep);
    if (!json->compact)
        JSON_INDENT();

    av_bprint_init(&buf, 1, AV_BPRINT_SIZE_UNLIMITED);
    printf("\"%s\": %lld", json_escape_str(&buf, key, wctx), value);
    av_bprint_finalize(&buf, NULL);
}

static const Writer json_writer = {
    .name                 = "json",
    .priv_size            = sizeof(JSONContext),
    .init                 = json_init,
    .print_section_header = json_print_section_header,
    .print_section_footer = json_print_section_footer,
    .print_integer        = json_print_int,
    .print_string         = json_print_str,
    .flags = WRITER_FLAG_PUT_PACKETS_AND_FRAMES_IN_SAME_CHAPTER,
    .priv_class           = &json_class,
};

/* XML output */

typedef struct {
    const AVClass *class;
    int within_tag;
    int indent_level;
    int fully_qualified;
    int xsd_strict;
} XMLContext;

#undef OFFSET
#define OFFSET(x) offsetof(XMLContext, x)

static const AVOption xml_options[] = {
    {"fully_qualified", "specify if the output should be fully qualified", OFFSET(fully_qualified), AV_OPT_TYPE_INT, {.i64=0},  0, 1 },
    {"q",               "specify if the output should be fully qualified", OFFSET(fully_qualified), AV_OPT_TYPE_INT, {.i64=0},  0, 1 },
    {"xsd_strict",      "ensure that the output is XSD compliant",         OFFSET(xsd_strict),      AV_OPT_TYPE_INT, {.i64=0},  0, 1 },
    {"x",               "ensure that the output is XSD compliant",         OFFSET(xsd_strict),      AV_OPT_TYPE_INT, {.i64=0},  0, 1 },
    {NULL},
};

DEFINE_WRITER_CLASS(xml);

static av_cold int xml_init(WriterContext *wctx)
{
    XMLContext *xml = wctx->priv;

    if (xml->xsd_strict) {
        xml->fully_qualified = 1;
#define CHECK_COMPLIANCE(opt, opt_name)                                 \
        if (opt) {                                                      \
            av_log(wctx, AV_LOG_ERROR,                                  \
                   "XSD-compliant output selected but option '%s' was selected, XML output may be non-compliant.\n" \
                   "You need to disable such option with '-no%s'\n", opt_name, opt_name); \
            return AVERROR(EINVAL);                                     \
        }
        CHECK_COMPLIANCE(show_private_data, "private");
        CHECK_COMPLIANCE(show_value_unit,   "unit");
        CHECK_COMPLIANCE(use_value_prefix,  "prefix");

        if (do_show_frames && do_show_packets) {
            av_log(wctx, AV_LOG_ERROR,
                   "Interleaved frames and packets are not allowed in XSD. "
                   "Select only one between the -show_frames and the -show_packets options.\n");
            return AVERROR(EINVAL);
        }
    }

    return 0;
}

static const char *xml_escape_str(AVBPrint *dst, const char *src, void *log_ctx)
{
    const char *p;

    for (p = src; *p; p++) {
        switch (*p) {
        case '&' : av_bprintf(dst, "%s", "&amp;");  break;
        case '<' : av_bprintf(dst, "%s", "&lt;");   break;
        case '>' : av_bprintf(dst, "%s", "&gt;");   break;
        case '"' : av_bprintf(dst, "%s", "&quot;"); break;
        case '\'': av_bprintf(dst, "%s", "&apos;"); break;
        default: av_bprint_chars(dst, *p, 1);
        }
    }

    return dst->str;
}

#define XML_INDENT() printf("%*c", xml->indent_level * 4, ' ')

static void xml_print_section_header(WriterContext *wctx)
{
    XMLContext *xml = wctx->priv;
    const struct section *section = wctx->section[wctx->level];
    const struct section *parent_section = wctx->level ?
        wctx->section[wctx->level-1] : NULL;

    if (wctx->level == 0) {
        const char *qual = " xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' "
            "xmlns:ffprobe='http://www.ffmpeg.org/schema/ffprobe' "
            "xsi:schemaLocation='http://www.ffmpeg.org/schema/ffprobe ffprobe.xsd'";

        printf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
        printf("<%sffprobe%s>\n",
               xml->fully_qualified ? "ffprobe:" : "",
               xml->fully_qualified ? qual : "");
        return;
    }

    if (xml->within_tag) {
        xml->within_tag = 0;
        printf(">\n");
    }
    if (section->flags & SECTION_FLAG_HAS_VARIABLE_FIELDS) {
        xml->indent_level++;
    } else {
        if (parent_section && (parent_section->flags & SECTION_FLAG_IS_WRAPPER) &&
            wctx->level && wctx->nb_item[wctx->level-1])
            printf("\n");
        xml->indent_level++;

        if (section->flags & SECTION_FLAG_IS_ARRAY) {
            XML_INDENT(); printf("<%s>\n", section->name);
        } else {
            XML_INDENT(); printf("<%s ", section->name);
            xml->within_tag = 1;
        }
    }
}

static void xml_print_section_footer(WriterContext *wctx)
{
    XMLContext *xml = wctx->priv;
    const struct section *section = wctx->section[wctx->level];

    if (wctx->level == 0) {
        printf("</%sffprobe>\n", xml->fully_qualified ? "ffprobe:" : "");
    } else if (xml->within_tag) {
        xml->within_tag = 0;
        printf("/>\n");
        xml->indent_level--;
    } else if (section->flags & SECTION_FLAG_HAS_VARIABLE_FIELDS) {
        xml->indent_level--;
    } else {
        XML_INDENT(); printf("</%s>\n", section->name);
        xml->indent_level--;
    }
}

static void xml_print_str(WriterContext *wctx, const char *key, const char *value)
{
    AVBPrint buf;
    XMLContext *xml = wctx->priv;
    const struct section *section = wctx->section[wctx->level];

    av_bprint_init(&buf, 1, AV_BPRINT_SIZE_UNLIMITED);

    if (section->flags & SECTION_FLAG_HAS_VARIABLE_FIELDS) {
        XML_INDENT();
        printf("<%s key=\"%s\"",
               section->element_name, xml_escape_str(&buf, key, wctx));
        av_bprint_clear(&buf);
        printf(" value=\"%s\"/>\n", xml_escape_str(&buf, value, wctx));
    } else {
        if (wctx->nb_item[wctx->level])
            printf(" ");
        printf("%s=\"%s\"", key, xml_escape_str(&buf, value, wctx));
    }

    av_bprint_finalize(&buf, NULL);
}

static void xml_print_int(WriterContext *wctx, const char *key, long long int value)
{
    if (wctx->nb_item[wctx->level])
        printf(" ");
    printf("%s=\"%lld\"", key, value);
}

static Writer xml_writer = {
    .name                 = "xml",
    .priv_size            = sizeof(XMLContext),
    .init                 = xml_init,
    .print_section_header = xml_print_section_header,
    .print_section_footer = xml_print_section_footer,
    .print_integer        = xml_print_int,
    .print_string         = xml_print_str,
    .flags = WRITER_FLAG_PUT_PACKETS_AND_FRAMES_IN_SAME_CHAPTER,
    .priv_class           = &xml_class,
};

static void writer_register_all(void)
{
    static int initialized;

    if (initialized)
        return;
    initialized = 1;

    writer_register(&default_writer);
    writer_register(&compact_writer);
    writer_register(&csv_writer);
    writer_register(&flat_writer);
    writer_register(&ini_writer);
    writer_register(&json_writer);
    writer_register(&xml_writer);
}

#define print_fmt(k, f, ...) do {              \
    av_bprint_clear(&pbuf);                    \
    av_bprintf(&pbuf, f, __VA_ARGS__);         \
    writer_print_string(w, k, pbuf.str, 0);    \
} while (0)

#define print_int(k, v)         writer_print_integer(w, k, v)
#define print_q(k, v, s)        writer_print_rational(w, k, v, s)
#define print_str(k, v)         writer_print_string(w, k, v, 0)
#define print_str_opt(k, v)     writer_print_string(w, k, v, PRINT_STRING_OPT)
#define print_str_validate(k, v) writer_print_string(w, k, v, PRINT_STRING_VALIDATE)
#define print_time(k, v, tb)    writer_print_time(w, k, v, tb, 0)
#define print_ts(k, v)          writer_print_ts(w, k, v, 0)
#define print_duration_time(k, v, tb) writer_print_time(w, k, v, tb, 1)
#define print_duration_ts(k, v)       writer_print_ts(w, k, v, 1)
#define print_val(k, v, u) do {                                     \
    struct unit_value uv;                                           \
    uv.val.i = v;                                                   \
    uv.unit = u;                                                    \
    writer_print_string(w, k, value_string(val_str, sizeof(val_str), uv), 0); \
} while (0)

#define print_section_header(s) writer_print_section_header(w, s)
#define print_section_footer(s) writer_print_section_footer(w, s)

static inline int show_tags(WriterContext *w, AVDictionary *tags, int section_id)
{
    AVDictionaryEntry *tag = NULL;
    int ret = 0;

    if (!tags)
        return 0;
    writer_print_section_header(w, section_id);

    while ((tag = av_dict_get(tags, "", tag, AV_DICT_IGNORE_SUFFIX))) {
        if ((ret = print_str_validate(tag->key, tag->value)) < 0)
            break;
    }
    writer_print_section_footer(w);

    return ret;
}

static void show_packet(WriterContext *w, AVFormatContext *fmt_ctx, AVPacket *pkt, int packet_idx)
{
    char val_str[128];
    AVStream *st = fmt_ctx->streams[pkt->stream_index];
    AVBPrint pbuf;
    const char *s;

    av_bprint_init(&pbuf, 1, AV_BPRINT_SIZE_UNLIMITED);

    writer_print_section_header(w, SECTION_ID_PACKET);

    s = av_get_media_type_string(st->codec->codec_type);
    if (s) print_str    ("codec_type", s);
    else   print_str_opt("codec_type", "unknown");
    print_int("stream_index",     pkt->stream_index);
    print_ts  ("pts",             pkt->pts);
    print_time("pts_time",        pkt->pts, &st->time_base);
    print_ts  ("dts",             pkt->dts);
    print_time("dts_time",        pkt->dts, &st->time_base);
    print_duration_ts("duration",        pkt->duration);
    print_duration_time("duration_time", pkt->duration, &st->time_base);
    print_duration_ts("convergence_duration", pkt->convergence_duration);
    print_duration_time("convergence_duration_time", pkt->convergence_duration, &st->time_base);
    print_val("size",             pkt->size, unit_byte_str);
    if (pkt->pos != -1) print_fmt    ("pos", "%"PRId64, pkt->pos);
    else                print_str_opt("pos", "N/A");
    print_fmt("flags", "%c",      pkt->flags & AV_PKT_FLAG_KEY ? 'K' : '_');
    if (do_show_data)
        writer_print_data(w, "data", pkt->data, pkt->size);
    writer_print_section_footer(w);

    av_bprint_finalize(&pbuf, NULL);
    fflush(stdout);
}

static void show_subtitle(WriterContext *w, AVSubtitle *sub, AVStream *stream,
                          AVFormatContext *fmt_ctx)
{
    AVBPrint pbuf;

    av_bprint_init(&pbuf, 1, AV_BPRINT_SIZE_UNLIMITED);

    writer_print_section_header(w, SECTION_ID_SUBTITLE);

    print_str ("media_type",         "subtitle");
    print_ts  ("pts",                 sub->pts);
    print_time("pts_time",            sub->pts, &AV_TIME_BASE_Q);
    print_int ("format",              sub->format);
    print_int ("start_display_time",  sub->start_display_time);
    print_int ("end_display_time",    sub->end_display_time);
    print_int ("num_rects",           sub->num_rects);

    writer_print_section_footer(w);

    av_bprint_finalize(&pbuf, NULL);
    fflush(stdout);
}

static void show_frame(WriterContext *w, AVFrame *frame, AVStream *stream,
                       AVFormatContext *fmt_ctx)
{
    AVBPrint pbuf;
    const char *s;

    av_bprint_init(&pbuf, 1, AV_BPRINT_SIZE_UNLIMITED);

    writer_print_section_header(w, SECTION_ID_FRAME);

    s = av_get_media_type_string(stream->codec->codec_type);
    if (s) print_str    ("media_type", s);
    else   print_str_opt("media_type", "unknown");
    print_int("key_frame",              frame->key_frame);
    print_ts  ("pkt_pts",               frame->pkt_pts);
    print_time("pkt_pts_time",          frame->pkt_pts, &stream->time_base);
    print_ts  ("pkt_dts",               frame->pkt_dts);
    print_time("pkt_dts_time",          frame->pkt_dts, &stream->time_base);
    print_duration_ts  ("pkt_duration",      av_frame_get_pkt_duration(frame));
    print_duration_time("pkt_duration_time", av_frame_get_pkt_duration(frame), &stream->time_base);
    if (av_frame_get_pkt_pos (frame) != -1) print_fmt    ("pkt_pos", "%"PRId64, av_frame_get_pkt_pos(frame));
    else                      print_str_opt("pkt_pos", "N/A");
    if (av_frame_get_pkt_size(frame) != -1) print_fmt    ("pkt_size", "%d", av_frame_get_pkt_size(frame));
    else                       print_str_opt("pkt_size", "N/A");

    switch (stream->codec->codec_type) {
        AVRational sar;

    case AVMEDIA_TYPE_VIDEO:
        print_int("width",                  frame->width);
        print_int("height",                 frame->height);
        s = av_get_pix_fmt_name(frame->format);
        if (s) print_str    ("pix_fmt", s);
        else   print_str_opt("pix_fmt", "unknown");
        sar = av_guess_sample_aspect_ratio(fmt_ctx, stream, frame);
        if (sar.num) {
            print_q("sample_aspect_ratio", sar, ':');
        } else {
            print_str_opt("sample_aspect_ratio", "N/A");
        }
        print_fmt("pict_type",              "%c", av_get_picture_type_char(frame->pict_type));
        print_int("coded_picture_number",   frame->coded_picture_number);
        print_int("display_picture_number", frame->display_picture_number);
        print_int("interlaced_frame",       frame->interlaced_frame);
        print_int("top_field_first",        frame->top_field_first);
        print_int("repeat_pict",            frame->repeat_pict);
        break;

    case AVMEDIA_TYPE_AUDIO:
        s = av_get_sample_fmt_name(frame->format);
        if (s) print_str    ("sample_fmt", s);
        else   print_str_opt("sample_fmt", "unknown");
        print_int("nb_samples",         frame->nb_samples);
        print_int("channels", av_frame_get_channels(frame));
        if (av_frame_get_channel_layout(frame)) {
            av_bprint_clear(&pbuf);
            av_bprint_channel_layout(&pbuf, av_frame_get_channels(frame),
                                     av_frame_get_channel_layout(frame));
            print_str    ("channel_layout", pbuf.str);
        } else
            print_str_opt("channel_layout", "unknown");
        break;
    }
    show_tags(w, av_frame_get_metadata(frame), SECTION_ID_FRAME_TAGS);

    writer_print_section_footer(w);

    av_bprint_finalize(&pbuf, NULL);
    fflush(stdout);
}

static av_always_inline int process_frame(WriterContext *w,
                                          AVFormatContext *fmt_ctx,
                                          AVFrame *frame, AVPacket *pkt)
{
    AVCodecContext *dec_ctx = fmt_ctx->streams[pkt->stream_index]->codec;
    AVSubtitle sub;
    int ret = 0, got_frame = 0;

    avcodec_get_frame_defaults(frame);
    if (dec_ctx->codec) {
        switch (dec_ctx->codec_type) {
        case AVMEDIA_TYPE_VIDEO:
            ret = avcodec_decode_video2(dec_ctx, frame, &got_frame, pkt);
            break;

        case AVMEDIA_TYPE_AUDIO:
            ret = avcodec_decode_audio4(dec_ctx, frame, &got_frame, pkt);
            break;

        case AVMEDIA_TYPE_SUBTITLE:
            ret = avcodec_decode_subtitle2(dec_ctx, &sub, &got_frame, pkt);
            break;
        }
    }

    if (ret < 0)
        return ret;
    ret = FFMIN(ret, pkt->size); /* guard against bogus return values */
    pkt->data += ret;
    pkt->size -= ret;
    if (got_frame) {
        int is_sub = (dec_ctx->codec_type == AVMEDIA_TYPE_SUBTITLE);
        nb_streams_frames[pkt->stream_index]++;
        if (do_show_frames)
            if (is_sub)
                show_subtitle(w, &sub, fmt_ctx->streams[pkt->stream_index], fmt_ctx);
            else
                show_frame(w, frame, fmt_ctx->streams[pkt->stream_index], fmt_ctx);
        if (is_sub)
            avsubtitle_free(&sub);
    }
    return got_frame;
}

static void log_read_interval(const ReadInterval *interval, void *log_ctx, int log_level)
{
    av_log(log_ctx, log_level, "id:%d", interval->id);

    if (interval->has_start) {
        av_log(log_ctx, log_level, " start:%s%s", interval->start_is_offset ? "+" : "",
               av_ts2timestr(interval->start, &AV_TIME_BASE_Q));
    } else {
        av_log(log_ctx, log_level, " start:N/A");
    }

    if (interval->has_end) {
        av_log(log_ctx, log_level, " end:%s", interval->end_is_offset ? "+" : "");
        if (interval->duration_frames)
            av_log(log_ctx, log_level, "#%"PRId64, interval->end);
        else
            av_log(log_ctx, log_level, "%s", av_ts2timestr(interval->end, &AV_TIME_BASE_Q));
    } else {
        av_log(log_ctx, log_level, " end:N/A");
    }

    av_log(log_ctx, log_level, "\n");
}

static int read_interval_packets(WriterContext *w, AVFormatContext *fmt_ctx,
                                 const ReadInterval *interval, int64_t *cur_ts)
{
    AVPacket pkt, pkt1;
    AVFrame frame;
    int ret = 0, i = 0, frame_count = 0;
    int64_t start = -INT64_MAX, end = interval->end;
    int has_start = 0, has_end = interval->has_end && !interval->end_is_offset;

    av_init_packet(&pkt);

    av_log(NULL, AV_LOG_VERBOSE, "Processing read interval ");
    log_read_interval(interval, NULL, AV_LOG_VERBOSE);

    if (interval->has_start) {
        int64_t target;
        if (interval->start_is_offset) {
            if (*cur_ts == AV_NOPTS_VALUE) {
                av_log(NULL, AV_LOG_ERROR,
                       "Could not seek to relative position since current "
                       "timestamp is not defined\n");
                ret = AVERROR(EINVAL);
                goto end;
            }
            target = *cur_ts + interval->start;
        } else {
            target = interval->start;
        }

        av_log(NULL, AV_LOG_VERBOSE, "Seeking to read interval start point %s\n",
               av_ts2timestr(target, &AV_TIME_BASE_Q));
        if ((ret = avformat_seek_file(fmt_ctx, -1, -INT64_MAX, target, INT64_MAX, 0)) < 0) {
            av_log(NULL, AV_LOG_ERROR, "Could not seek to position %"PRId64": %s\n",
                   interval->start, av_err2str(ret));
            goto end;
        }
    }

    while (!av_read_frame(fmt_ctx, &pkt)) {
        if (selected_streams[pkt.stream_index]) {
            AVRational tb = fmt_ctx->streams[pkt.stream_index]->time_base;

            if (pkt.pts != AV_NOPTS_VALUE)
                *cur_ts = av_rescale_q(pkt.pts, tb, AV_TIME_BASE_Q);

            if (!has_start && *cur_ts != AV_NOPTS_VALUE) {
                start = *cur_ts;
                has_start = 1;
            }

            if (has_start && !has_end && interval->end_is_offset) {
                end = start + interval->end;
                has_end = 1;
            }

            if (interval->end_is_offset && interval->duration_frames) {
                if (frame_count >= interval->end)
                    break;
            } else if (has_end && *cur_ts != AV_NOPTS_VALUE && *cur_ts >= end) {
                break;
            }

            frame_count++;
            if (do_read_packets) {
                if (do_show_packets)
                    show_packet(w, fmt_ctx, &pkt, i++);
                nb_streams_packets[pkt.stream_index]++;
            }
            if (do_read_frames) {
                pkt1 = pkt;
                while (pkt1.size && process_frame(w, fmt_ctx, &frame, &pkt1) > 0);
            }
        }
        av_free_packet(&pkt);
    }
    av_init_packet(&pkt);
    pkt.data = NULL;
    pkt.size = 0;
    //Flush remaining frames that are cached in the decoder
    for (i = 0; i < fmt_ctx->nb_streams; i++) {
        pkt.stream_index = i;
        if (do_read_frames)
            while (process_frame(w, fmt_ctx, &frame, &pkt) > 0);
    }

end:
    if (ret < 0) {
        av_log(NULL, AV_LOG_ERROR, "Could not read packets in interval ");
        log_read_interval(interval, NULL, AV_LOG_ERROR);
    }
    return ret;
}

static int read_packets(WriterContext *w, AVFormatContext *fmt_ctx)
{
    int i, ret = 0;
    int64_t cur_ts = fmt_ctx->start_time;

    if (read_intervals_nb == 0) {
        ReadInterval interval = (ReadInterval) { .has_start = 0, .has_end = 0 };
        ret = read_interval_packets(w, fmt_ctx, &interval, &cur_ts);
    } else {
        for (i = 0; i < read_intervals_nb; i++) {
            ret = read_interval_packets(w, fmt_ctx, &read_intervals[i], &cur_ts);
            if (ret < 0)
                break;
        }
    }

    return ret;
}

static int show_stream(WriterContext *w, AVFormatContext *fmt_ctx, int stream_idx, int in_program)
{
    AVStream *stream = fmt_ctx->streams[stream_idx];
    AVCodecContext *dec_ctx;
    const AVCodec *dec;
    char val_str[128];
    const char *s;
    AVRational sar, dar;
    AVBPrint pbuf;
    int ret = 0;

    av_bprint_init(&pbuf, 1, AV_BPRINT_SIZE_UNLIMITED);

    writer_print_section_header(w, in_program ? SECTION_ID_PROGRAM_STREAM : SECTION_ID_STREAM);

    print_int("index", stream->index);

    if ((dec_ctx = stream->codec)) {
        const char *profile = NULL;
        dec = dec_ctx->codec;
        if (dec) {
            print_str("codec_name", dec->name);
            if (!do_bitexact) {
                if (dec->long_name) print_str    ("codec_long_name", dec->long_name);
                else                print_str_opt("codec_long_name", "unknown");
            }
        } else {
            print_str_opt("codec_name", "unknown");
            if (!do_bitexact) {
                print_str_opt("codec_long_name", "unknown");
            }
        }

        if (dec && (profile = av_get_profile_name(dec, dec_ctx->profile)))
            print_str("profile", profile);
        else
            print_str_opt("profile", "unknown");

        s = av_get_media_type_string(dec_ctx->codec_type);
        if (s) print_str    ("codec_type", s);
        else   print_str_opt("codec_type", "unknown");
        print_q("codec_time_base", dec_ctx->time_base, '/');

        /* print AVI/FourCC tag */
        av_get_codec_tag_string(val_str, sizeof(val_str), dec_ctx->codec_tag);
        print_str("codec_tag_string",    val_str);
        print_fmt("codec_tag", "0x%04x", dec_ctx->codec_tag);