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mpegts: Replace the MP4 descriptor parser with a recursive parser.

This commit is contained in:
Alex Converse 2011-10-05 11:04:42 -07:00
parent c3bc6096f2
commit fec2836483
1 changed files with 139 additions and 33 deletions
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172
libavformat/mpegts.c
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@ -870,41 +870,150 @@ static PESContext *add_pes_stream(MpegTSContext *ts, int pid, int pcr_pid)
return pes;
}
static int mp4_read_iods(AVFormatContext *s, const uint8_t *buf, unsigned size,
int *es_id, uint8_t **dec_config_descr,
int *dec_config_descr_size)
{
#define MAX_LEVEL 4
typedef struct {
AVFormatContext *s;
AVIOContext pb;
int tag;
unsigned len;
Mp4Descr *descr;
Mp4Descr *active_descr;
int descr_count;
int max_descr_count;
int level;
} MP4DescrParseContext;
ffio_init_context(&pb, buf, size, 0, NULL, NULL, NULL, NULL);
static int init_MP4DescrParseContext(
MP4DescrParseContext *d, AVFormatContext *s, const uint8_t *buf,
unsigned size, Mp4Descr *descr, int max_descr_count)
{
int ret;
if (size > (1<<30))
return AVERROR_INVALIDDATA;
len = ff_mp4_read_descr(s, &pb, &tag);
if (tag == MP4IODescrTag) {
avio_rb16(&pb); // ID
avio_r8(&pb);
avio_r8(&pb);
avio_r8(&pb);
avio_r8(&pb);
avio_r8(&pb);
len = ff_mp4_read_descr(s, &pb, &tag);
if (tag == MP4ESDescrTag) {
ff_mp4_parse_es_descr(&pb, es_id);
av_dlog(s, "ES_ID %#x\n", *es_id);
len = ff_mp4_read_descr(s, &pb, &tag);
if (tag == MP4DecConfigDescrTag) {
*dec_config_descr = av_malloc(len);
if (!*dec_config_descr)
return AVERROR(ENOMEM);
*dec_config_descr_size = len;
avio_read(&pb, *dec_config_descr, len);
}
}
if ((ret = ffio_init_context(&d->pb, (unsigned char*)buf, size, 0,
NULL, NULL, NULL, NULL)) < 0)
return ret;
d->s = s;
d->level = 0;
d->descr_count = 0;
d->descr = descr;
d->active_descr = NULL;
d->max_descr_count = max_descr_count;
return 0;
}
static void update_offsets(AVIOContext *pb, int64_t *off, int *len) {
int64_t new_off = avio_tell(pb);
(*len) -= new_off - *off;
*off = new_off;
}
static int parse_mp4_descr(MP4DescrParseContext *d, int64_t off, int len,
int target_tag);
static int parse_mp4_descr_arr(MP4DescrParseContext *d, int64_t off, int len)
{
while (len > 0) {
if (parse_mp4_descr(d, off, len, 0) < 0)
return -1;
update_offsets(&d->pb, &off, &len);
}
return 0;
}
static int parse_MP4IODescrTag(MP4DescrParseContext *d, int64_t off, int len)
{
avio_rb16(&d->pb); // ID
avio_r8(&d->pb);
avio_r8(&d->pb);
avio_r8(&d->pb);
avio_r8(&d->pb);
avio_r8(&d->pb);
update_offsets(&d->pb, &off, &len);
return parse_mp4_descr_arr(d, off, len);
}
static int parse_MP4ESDescrTag(MP4DescrParseContext *d, int64_t off, int len)
{
int es_id = 0;
if (d->descr_count >= d->max_descr_count)
return -1;
ff_mp4_parse_es_descr(&d->pb, &es_id);
d->active_descr = d->descr + (d->descr_count++);
d->active_descr->es_id = es_id;
update_offsets(&d->pb, &off, &len);
parse_mp4_descr(d, off, len, MP4DecConfigDescrTag);
//SLConfigDescriptor
d->active_descr = NULL;
return 0;
}
static int parse_MP4DecConfigDescrTag(MP4DescrParseContext *d, int64_t off, int len)
{
Mp4Descr *descr = d->active_descr;
if (!descr)
return -1;
d->active_descr->dec_config_descr = av_malloc(len);
if (!descr->dec_config_descr)
return AVERROR(ENOMEM);
descr->dec_config_descr_len = len;
avio_read(&d->pb, descr->dec_config_descr, len);
return 0;
}
static int parse_mp4_descr(MP4DescrParseContext *d, int64_t off, int len,
int target_tag) {
int tag;
int len1 = ff_mp4_read_descr(d->s, &d->pb, &tag);
update_offsets(&d->pb, &off, &len);
if (len < 0 || len1 > len || len1 <= 0) {
av_log(d->s, AV_LOG_ERROR, "Tag %x length violation new length %d bytes remaining %d\n", tag, len1, len);
return -1;
}
if (d->level++ >= MAX_LEVEL) {
av_log(d->s, AV_LOG_ERROR, "Maximum MP4 descriptor level exceeded\n");
goto done;
}
if (target_tag && tag != target_tag) {
av_log(d->s, AV_LOG_ERROR, "Found tag %x expected %x\n", tag, target_tag);
goto done;
}
switch (tag) {
case MP4IODescrTag:
parse_MP4IODescrTag(d, off, len1);
break;
case MP4ESDescrTag:
parse_MP4ESDescrTag(d, off, len1);
break;
case MP4DecConfigDescrTag:
parse_MP4DecConfigDescrTag(d, off, len1);
break;
}
done:
d->level--;
avio_seek(&d->pb, off + len1, SEEK_SET);
return 0;
}
static int mp4_read_iods(AVFormatContext *s, const uint8_t *buf, unsigned size,
Mp4Descr *descr, int *descr_count, int max_descr_count)
{
MP4DescrParseContext d;
if (init_MP4DescrParseContext(&d, s, buf, size, descr, max_descr_count) < 0)
return -1;
parse_mp4_descr(&d, avio_tell(&d.pb), size, MP4IODescrTag);
*descr_count = d.descr_count;
return 0;
}
int ff_parse_mpeg2_descriptor(AVFormatContext *fc, AVStream *st, int stream_type,
const uint8_t **pp, const uint8_t *desc_list_end,
Mp4Descr *mp4_descr, int mp4_descr_count, int pid)
@ -1080,11 +1189,8 @@ static void pmt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len
get8(&p, p_end); // scope
get8(&p, p_end); // label
len -= 2;
if (mp4_descr_count < MAX_MP4_DESCR_COUNT) {
mp4_descr_count++;
mp4_read_iods(ts->stream, p, len, &mp4_descr->es_id,
&mp4_descr->dec_config_descr, &mp4_descr->dec_config_descr_len);
}
mp4_read_iods(ts->stream, p, len, mp4_descr + mp4_descr_count,
&mp4_descr_count, MAX_MP4_DESCR_COUNT);
} else if (tag == 0x05 && len >= 4) { // registration descriptor
prog_reg_desc = bytestream_get_le32(&p);
len -= 4;