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mpegts: relax restrictions on matching the packet start in read_header

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analyze() is currently called both when probing and from read_header().
It determines the packet start by looking for the sync byte, followed by
unset Transport Error Indicator and valid adaptation_field_control.

This makes sense to do when probing, but once we already know the format
is MPEG-TS, it is counterproductive to be so strict -- e.g. in some
files the TEI might be set and analyze() might get called with a smaller
buffer than the one used for probing, resulting in a failure.
This commit is contained in:
Anton Khirnov 2015-02-04 12:37:01 +01:00
parent 6a5b8ca432
commit 1509c018bd
1 changed files with 10 additions and 8 deletions
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18
libavformat/mpegts.c
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@ -425,7 +425,8 @@ static void mpegts_close_filter(MpegTSContext *ts, MpegTSFilter *filter)
ts->pids[pid] = NULL; ts->pids[pid] = NULL;
} }
static int analyze(const uint8_t *buf, int size, int packet_size, int *index) static int analyze(const uint8_t *buf, int size, int packet_size, int *index,
int probe)
{ {
int stat[TS_MAX_PACKET_SIZE]; int stat[TS_MAX_PACKET_SIZE];
int i; int i;
@ -435,7 +436,8 @@ static int analyze(const uint8_t *buf, int size, int packet_size, int *index)
memset(stat, 0, packet_size * sizeof(int)); memset(stat, 0, packet_size * sizeof(int));
for (x = i = 0; i < size - 3; i++) { for (x = i = 0; i < size - 3; i++) {
if (buf[i] == 0x47 && !(buf[i + 1] & 0x80) && (buf[i + 3] & 0x30)) { if (buf[i] == 0x47 &&
(!probe || (!(buf[i + 1] & 0x80) && (buf[i + 3] & 0x30)))) {
stat[x]++; stat[x]++;
if (stat[x] > best_score) { if (stat[x] > best_score) {
best_score = stat[x]; best_score = stat[x];
@ -460,9 +462,9 @@ static int get_packet_size(const uint8_t *buf, int size)
if (size < (TS_FEC_PACKET_SIZE * 5 + 1)) if (size < (TS_FEC_PACKET_SIZE * 5 + 1))
return AVERROR_INVALIDDATA; return AVERROR_INVALIDDATA;
score = analyze(buf, size, TS_PACKET_SIZE, NULL); score = analyze(buf, size, TS_PACKET_SIZE, NULL, 0);
dvhs_score = analyze(buf, size, TS_DVHS_PACKET_SIZE, NULL); dvhs_score = analyze(buf, size, TS_DVHS_PACKET_SIZE, NULL, 0);
fec_score = analyze(buf, size, TS_FEC_PACKET_SIZE, NULL); fec_score = analyze(buf, size, TS_FEC_PACKET_SIZE, NULL, 0);
av_dlog(NULL, "score: %d, dvhs_score: %d, fec_score: %d \n", av_dlog(NULL, "score: %d, dvhs_score: %d, fec_score: %d \n",
score, dvhs_score, fec_score); score, dvhs_score, fec_score);
@ -1986,11 +1988,11 @@ static int mpegts_probe(AVProbeData *p)
return AVERROR_INVALIDDATA; return AVERROR_INVALIDDATA;
score = analyze(p->buf, TS_PACKET_SIZE * check_count, score = analyze(p->buf, TS_PACKET_SIZE * check_count,
TS_PACKET_SIZE, NULL) * CHECK_COUNT / check_count; TS_PACKET_SIZE, NULL, 1) * CHECK_COUNT / check_count;
dvhs_score = analyze(p->buf, TS_DVHS_PACKET_SIZE * check_count, dvhs_score = analyze(p->buf, TS_DVHS_PACKET_SIZE * check_count,
TS_DVHS_PACKET_SIZE, NULL) * CHECK_COUNT / check_count; TS_DVHS_PACKET_SIZE, NULL, 1) * CHECK_COUNT / check_count;
fec_score = analyze(p->buf, TS_FEC_PACKET_SIZE * check_count, fec_score = analyze(p->buf, TS_FEC_PACKET_SIZE * check_count,
TS_FEC_PACKET_SIZE, NULL) * CHECK_COUNT / check_count; TS_FEC_PACKET_SIZE, NULL, 1) * CHECK_COUNT / check_count;
av_dlog(NULL, "score: %d, dvhs_score: %d, fec_score: %d \n", av_dlog(NULL, "score: %d, dvhs_score: %d, fec_score: %d \n",
score, dvhs_score, fec_score); score, dvhs_score, fec_score);