Commit 0bd4e5d1 authored by Tim-Philipp Müller's avatar Tim-Philipp Müller
Browse files

typefinding: more fine-grained matroska/webm typefinding

Typefind to audio/x-matroska, video/x-matroska, audio/webm,
video/webm and video/x-matroska-3d.

http://www.webmproject.org/code/specs/container/#naming
http://matroska.org/technical/specs/notes.html
parent 9ea22283
......@@ -3435,76 +3435,256 @@ ircam_type_find (GstTypeFind * tf, gpointer ununsed)
}
}
/* EBML typefind helper */
static gboolean
ebml_check_header (GstTypeFind * tf, const gchar * doctype, int doctype_len)
/*** Matroska/WebM ***/
#define EBML_HEADER 0x1A45DFA3
#define EBML_VERSION 0x4286
#define EBML_DOCTYPE 0x4282
#define EBML_DOCTYPE_VERSION 0x4287
#define MATROSKA_SEGMENT 0x18538067
#define MATROSKA_CLUSTER 0x1F43B675
#define MATROSKA_TRACKS 0x1654AE6B
#define MATROSKA_TRACK_ENTRY 0xAE
#define MATROSKA_TRACK_TYPE 0x83
#define MATROSKA_STEREO_MODE 0x53B8
#define EBML_MAX_LEN (2 * 1024 * 1024)
typedef enum
{
/* 4 bytes for EBML ID, 1 byte for header length identifier */
const guint8 *data = gst_type_find_peek (tf, 0, 4 + 1);
gint len_mask = 0x80, size = 1, n = 1, total;
EBML_DOCTYPE_UNKNOWN = 0,
EBML_DOCTYPE_MATROSKA,
EBML_DOCTYPE_WEBM
} GstEbmlDocType;
if (!data)
return FALSE;
typedef struct
{
GstEbmlDocType doctype;
guint audio;
guint video;
guint other;
guint video_stereo;
guint chunks;
guint tracks_ok; /* if we've seen and fully parsed the TRACKS element */
} GstMatroskaInfo;
/* ebml header? */
if (data[0] != 0x1A || data[1] != 0x45 || data[2] != 0xDF || data[3] != 0xA3)
return FALSE;
static inline guint
ebml_read_chunk_header (GstTypeFind * tf, DataScanCtx * c, guint max_size,
guint32 * id, guint64 * size)
{
guint64 mask;
guint msbit_set, i, len, id_len;
if (c->size < 12 || max_size < 1)
return 0;
/* length of header */
total = data[4];
while (size <= 8 && !(total & len_mask)) {
size++;
len_mask >>= 1;
/* element ID */
*id = c->data[0];
if ((c->data[0] & 0x80) == 0x80) {
id_len = 1;
} else if ((c->data[0] & 0xC0) == 0x40) {
id_len = 2;
} else if ((c->data[0] & 0xE0) == 0x20) {
id_len = 3;
} else if ((c->data[0] & 0xF0) == 0x10) {
id_len = 4;
} else {
return 0;
}
if (size > 8)
return FALSE;
total &= (len_mask - 1);
while (n < size)
total = (total << 8) | data[4 + n++];
/* get new data for full header, 4 bytes for EBML ID,
* EBML length tag and the actual header */
data = gst_type_find_peek (tf, 0, 4 + size + total);
if (!data)
if (max_size < id_len)
return 0;
for (i = 1; i < id_len; ++i) {
*id = (*id << 8) | c->data[i];
}
data_scan_ctx_advance (tf, c, id_len);
max_size -= id_len;
/* size */
if (max_size < 1 || c->data[0] == 0)
return 0;
msbit_set = g_bit_nth_msf (c->data[0], 8);
mask = ((1 << msbit_set) - 1);
*size = c->data[0] & mask;
len = 7 - msbit_set;
if (max_size < 1 + len)
return 0;
for (i = 0; i < len; ++i) {
mask = (mask << 8) | 0xff;
*size = (*size << 8) | c->data[1 + i];
}
data_scan_ctx_advance (tf, c, 1 + len);
/* undefined/unknown size? (all bits 1) */
if (*size == mask) {
/* allow unknown size for SEGMENT chunk, bail out otherwise */
if (*id == MATROSKA_SEGMENT)
*size = G_MAXUINT64;
else
return 0;
}
return id_len + (1 + len);
}
static gboolean
ebml_parse_chunk (GstTypeFind * tf, DataScanCtx * ctx, guint32 chunk_id,
guint chunk_size, GstMatroskaInfo * info, guint depth)
{ /* FIXME: make sure input size is clipped to 32 bit */
static const gchar SPACES[] = " ";
DataScanCtx c = *ctx;
guint64 element_size;
guint32 id, hdr_len;
if (depth >= 8) /* keep SPACES large enough for depth */
return FALSE;
/* only check doctype if asked to do so */
if (doctype == NULL || doctype_len == 0)
return TRUE;
while (chunk_size > 0) {
if (c.offset > EBML_MAX_LEN || !data_scan_ctx_ensure_data (tf, &c, 64))
return FALSE;
/* the header must contain the doctype. For now, we don't parse the
* whole header but simply check for the availability of that array
* of characters inside the header. Not fully fool-proof, but good
* enough. */
for (n = 4 + size; n <= 4 + size + total - doctype_len; n++)
if (!memcmp (&data[n], doctype, doctype_len))
return TRUE;
hdr_len = ebml_read_chunk_header (tf, &c, chunk_size, &id, &element_size);
if (hdr_len == 0)
return FALSE;
return FALSE;
g_assert (hdr_len <= chunk_size);
chunk_size -= hdr_len;
if (element_size > chunk_size)
return FALSE;
GST_DEBUG ("%s %08x, size %" G_GUINT64_FORMAT " / %" G_GUINT64_FORMAT,
SPACES + sizeof (SPACES) - 1 - (2 * depth), id, element_size,
hdr_len + element_size);
if (!data_scan_ctx_ensure_data (tf, &c, element_size)) {
GST_DEBUG ("not enough data");
return FALSE;
}
switch (id) {
case EBML_DOCTYPE:
if (element_size >= 8 && memcmp (c.data, "matroska", 8) == 0)
info->doctype = EBML_DOCTYPE_MATROSKA;
else if (element_size >= 4 && memcmp (c.data, "webm", 4) == 0)
info->doctype = EBML_DOCTYPE_WEBM;
break;
case MATROSKA_SEGMENT:
GST_LOG ("parsing segment");
ebml_parse_chunk (tf, &c, id, element_size, info, depth + 1);
GST_LOG ("parsed segment, done");
return FALSE;
case MATROSKA_TRACKS:
GST_LOG ("parsing tracks");
info->tracks_ok =
ebml_parse_chunk (tf, &c, id, element_size, info, depth + 1);
GST_LOG ("parsed tracks: %s, done (after %" G_GUINT64_FORMAT " bytes)",
info->tracks_ok ? "ok" : "FAIL", c.offset + element_size);
return FALSE;
case MATROSKA_TRACK_ENTRY:
GST_LOG ("parsing track entry");
if (!ebml_parse_chunk (tf, &c, id, element_size, info, depth + 1))
return FALSE;
break;
case MATROSKA_TRACK_TYPE:{
guint type = 0, i;
/* is supposed to always be 1-byte, but not everyone's following that */
for (i = 0; i < element_size; ++i)
type = (type << 8) | c.data[i];
GST_DEBUG ("%s track type %u",
SPACES + sizeof (SPACES) - 1 - (2 * depth), type);
if (type == 1)
++info->video;
else if (c.data[0] == 2)
++info->audio;
else
++info->other;
break;
}
case MATROSKA_STEREO_MODE:
++info->video_stereo;
break;
case MATROSKA_CLUSTER:
GST_WARNING ("cluster, bailing out (should've found tracks by now)");
return FALSE;
default:
break;
}
data_scan_ctx_advance (tf, &c, element_size);
chunk_size -= element_size;
++info->chunks;
}
return TRUE;
}
/*** video/x-matroska ***/
static GstStaticCaps matroska_caps = GST_STATIC_CAPS ("video/x-matroska");
#define MATROSKA_CAPS (gst_static_caps_get(&matroska_caps))
static void
matroska_type_find (GstTypeFind * tf, gpointer ununsed)
{
if (ebml_check_header (tf, "matroska", 8))
gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, MATROSKA_CAPS);
else if (ebml_check_header (tf, NULL, 0))
gst_type_find_suggest (tf, GST_TYPE_FIND_LIKELY, MATROSKA_CAPS);
}
GstTypeFindProbability prob;
GstMatroskaInfo info = { 0, };
const gchar *type_name;
DataScanCtx c = { 0, NULL, 0 };
gboolean is_audio;
guint64 size;
guint32 id, hdr_len;
/*** video/webm ***/
static GstStaticCaps webm_caps = GST_STATIC_CAPS ("video/webm");
if (!data_scan_ctx_ensure_data (tf, &c, 64))
return;
#define WEBM_CAPS (gst_static_caps_get(&webm_caps))
static void
webm_type_find (GstTypeFind * tf, gpointer ununsed)
{
if (ebml_check_header (tf, "webm", 4))
gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, WEBM_CAPS);
if (GST_READ_UINT32_BE (c.data) != EBML_HEADER)
return;
while (c.offset < EBML_MAX_LEN && data_scan_ctx_ensure_data (tf, &c, 64)) {
hdr_len = ebml_read_chunk_header (tf, &c, c.size, &id, &size);
if (hdr_len == 0)
return;
GST_INFO ("=== top-level chunk %08x, size %" G_GUINT64_FORMAT
" / %" G_GUINT64_FORMAT, id, size, size + hdr_len);
if (!ebml_parse_chunk (tf, &c, id, size, &info, 0))
break;
data_scan_ctx_advance (tf, &c, size);
GST_INFO ("=== done with chunk %08x", id);
if (id == MATROSKA_SEGMENT)
break;
}
GST_INFO ("audio=%u video=%u other=%u chunks=%u doctype=%d all_tracks=%d",
info.audio, info.video, info.other, info.chunks, info.doctype,
info.tracks_ok);
/* perhaps we should bail out if tracks_ok is FALSE and wait for more data?
* (we would need new API to signal this properly and prevent other
* typefinders from taking over the decision then) */
is_audio = (info.audio > 0 && info.video == 0 && info.other == 0);
if (info.doctype == EBML_DOCTYPE_WEBM) {
type_name = (is_audio) ? "audio/webm" : "video/webm";
} else if (info.video > 0 && info.video_stereo) {
type_name = "video/x-matroska-3d";
} else {
type_name = (is_audio) ? "audio/x-matroska" : "video/x-matroska";
}
if (info.doctype == EBML_DOCTYPE_UNKNOWN)
prob = GST_TYPE_FIND_LIKELY;
else
prob = GST_TYPE_FIND_MAXIMUM;
gst_type_find_suggest_simple (tf, prob, type_name, NULL);
}
/*** application/mxf ***/
......@@ -4638,9 +4818,7 @@ plugin_init (GstPlugin * plugin)
TYPE_FIND_REGISTER (plugin, "image/x-portable-pixmap", GST_RANK_SECONDARY,
pnm_type_find, "pnm,ppm,pgm,pbm", PNM_CAPS, NULL, NULL);
TYPE_FIND_REGISTER (plugin, "video/x-matroska", GST_RANK_PRIMARY,
matroska_type_find, "mkv,mka", MATROSKA_CAPS, NULL, NULL);
TYPE_FIND_REGISTER (plugin, "video/webm", GST_RANK_PRIMARY, webm_type_find,
"webm", WEBM_CAPS, NULL, NULL);
matroska_type_find, "mkv,mka,mk3d,webm", MATROSKA_CAPS, NULL, NULL);
TYPE_FIND_REGISTER (plugin, "application/mxf", GST_RANK_PRIMARY,
mxf_type_find, "mxf", MXF_CAPS, NULL, NULL);
TYPE_FIND_REGISTER_START_WITH (plugin, "video/x-mve", GST_RANK_SECONDARY,
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment