From 63511324358401ac739093c379f80fae02b5e6c3 Mon Sep 17 00:00:00 2001 From: Aurelien Jacobs Date: Tue, 5 Aug 2008 00:40:02 +0000 Subject: [PATCH] matroskadec: use generic ebml parser to parse ebml header Originally committed as revision 14553 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavformat/matroskadec.c | 176 ++++++++------------------------------ 1 file changed, 35 insertions(+), 141 deletions(-) diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c index 6a1aeb2794..3749bcccf5 100644 --- a/libavformat/matroskadec.c +++ b/libavformat/matroskadec.c @@ -80,6 +80,14 @@ typedef struct { int64_t pos; } EbmlBin; +typedef struct { + uint64_t version; + uint64_t max_size; + uint64_t id_length; + char *doctype; + uint64_t doctype_version; +} Ebml; + typedef struct Track { MatroskaTrackType type; @@ -203,6 +211,23 @@ typedef struct MatroskaDemuxContext { #define ARRAY_SIZE(x) (sizeof(x)/sizeof(*x)) +static EbmlSyntax ebml_header[] = { + { EBML_ID_EBMLREADVERSION, EBML_UINT, 0, offsetof(Ebml,version), {.u=EBML_VERSION} }, + { EBML_ID_EBMLMAXSIZELENGTH, EBML_UINT, 0, offsetof(Ebml,max_size), {.u=8} }, + { EBML_ID_EBMLMAXIDLENGTH, EBML_UINT, 0, offsetof(Ebml,id_length), {.u=4} }, + { EBML_ID_DOCTYPE, EBML_STR, 0, offsetof(Ebml,doctype), {.s="(none)"} }, + { EBML_ID_DOCTYPEREADVERSION, EBML_UINT, 0, offsetof(Ebml,doctype_version), {.u=1} }, + { EBML_ID_EBMLVERSION, EBML_NONE }, + { EBML_ID_DOCTYPEVERSION, EBML_NONE }, + { EBML_ID_VOID, EBML_NONE }, + { 0 } +}; + +static EbmlSyntax ebml_syntax[] = { + { EBML_ID_HEADER, EBML_NEST, 0, 0, {.n=ebml_header} }, + { 0 } +}; + /* * The first few functions handle EBML file parsing. The rest * is the document interpretation. Matroska really just is a @@ -694,130 +719,6 @@ matroska_ebmlnum_sint (uint8_t *data, return res; } -/* - * Read an EBML header. - * 0 is success, < 0 is failure. - */ - -static int -ebml_read_header (MatroskaDemuxContext *matroska, - char **doctype, - int *version) -{ - uint32_t id; - int level_up, res = 0; - - /* default init */ - if (doctype) - *doctype = NULL; - if (version) - *version = 1; - - if (!(id = ebml_peek_id(matroska, &level_up)) || - level_up != 0 || id != EBML_ID_HEADER) { - av_log(matroska->ctx, AV_LOG_ERROR, - "This is not an EBML file (id=0x%x/0x%x)\n", id, EBML_ID_HEADER); - return AVERROR_INVALIDDATA; - } - if ((res = ebml_read_master(matroska, &id)) < 0) - return res; - - while (res == 0) { - if (!(id = ebml_peek_id(matroska, &level_up))) - return AVERROR(EIO); - - /* end-of-header */ - if (level_up) - break; - - switch (id) { - /* is our read version uptodate? */ - case EBML_ID_EBMLREADVERSION: { - uint64_t num; - - if ((res = ebml_read_uint(matroska, &id, &num)) < 0) - return res; - if (num > EBML_VERSION) { - av_log(matroska->ctx, AV_LOG_ERROR, - "EBML version %"PRIu64" (> %d) is not supported\n", - num, EBML_VERSION); - return AVERROR_INVALIDDATA; - } - break; - } - - /* we only handle 8 byte lengths at max */ - case EBML_ID_EBMLMAXSIZELENGTH: { - uint64_t num; - - if ((res = ebml_read_uint(matroska, &id, &num)) < 0) - return res; - if (num > sizeof(uint64_t)) { - av_log(matroska->ctx, AV_LOG_ERROR, - "Integers of size %"PRIu64" (> %zd) not supported\n", - num, sizeof(uint64_t)); - return AVERROR_INVALIDDATA; - } - break; - } - - /* we handle 4 byte IDs at max */ - case EBML_ID_EBMLMAXIDLENGTH: { - uint64_t num; - - if ((res = ebml_read_uint(matroska, &id, &num)) < 0) - return res; - if (num > sizeof(uint32_t)) { - av_log(matroska->ctx, AV_LOG_ERROR, - "IDs of size %"PRIu64" (> %zu) not supported\n", - num, sizeof(uint32_t)); - return AVERROR_INVALIDDATA; - } - break; - } - - case EBML_ID_DOCTYPE: { - char *text; - - if ((res = ebml_read_ascii(matroska, &id, &text)) < 0) - return res; - if (doctype) { - if (*doctype) - av_free(*doctype); - *doctype = text; - } else - av_free(text); - break; - } - - case EBML_ID_DOCTYPEREADVERSION: { - uint64_t num; - - if ((res = ebml_read_uint(matroska, &id, &num)) < 0) - return res; - if (version) - *version = num; - break; - } - - default: - av_log(matroska->ctx, AV_LOG_INFO, - "Unknown data type 0x%x in EBML header", id); - /* pass-through */ - - case EBML_ID_VOID: - /* we ignore these two, as they don't tell us anything we - * care about */ - case EBML_ID_EBMLVERSION: - case EBML_ID_DOCTYPEVERSION: - res = ebml_read_skip (matroska); - break; - } - } - - return 0; -} - static int matroska_find_track_by_num (MatroskaDemuxContext *matroska, @@ -2500,31 +2401,24 @@ matroska_read_header (AVFormatContext *s, AVFormatParameters *ap) { MatroskaDemuxContext *matroska = s->priv_data; - char *doctype; - int version, last_level, res = 0; + int last_level, res = 0; + Ebml ebml = { 0 }; uint32_t id; matroska->ctx = s; /* First read the EBML header. */ - doctype = NULL; - if ((res = ebml_read_header(matroska, &doctype, &version)) < 0) - return res; - if ((doctype == NULL) || strcmp(doctype, "matroska")) { - av_log(matroska->ctx, AV_LOG_ERROR, - "Wrong EBML doctype ('%s' != 'matroska').\n", - doctype ? doctype : "(none)"); - if (doctype) - av_free(doctype); - return AVERROR_NOFMT; - } - av_free(doctype); - if (version > 2) { + if (ebml_parse(matroska, ebml_syntax, &ebml, 0, 1) + || ebml.version > EBML_VERSION || ebml.max_size > sizeof(uint64_t) + || ebml.id_length > sizeof(uint32_t) || strcmp(ebml.doctype, "matroska") + || ebml.doctype_version > 2) { av_log(matroska->ctx, AV_LOG_ERROR, - "Matroska demuxer version 2 too old for file version %d\n", - version); + "EBML header using unsupported features\n" + "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n", + ebml.version, ebml.doctype, ebml.doctype_version); return AVERROR_NOFMT; } + ebml_free(ebml_syntax, &ebml); /* The next thing is a segment. */ while (1) {