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Fix FS#13009.

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This file revealed several problems with our ASF parser:

1)  The packet count in the ASF was actually a 64 bit value,
leading to overflow in very long files.

2)  Seeking blindly trusted the bitrate listed in the ASF header
rather than computing it from the packet size and number of packets.

Fix these problems and fix a few minor issues.

Change-Id: Ie0f68734e6423e837757528ddb155f3bdcc979f3
This commit is contained in:
Michael Giacomelli 2014-11-28 22:25:23 +01:00
parent 0cd9e4e6bc
commit aa2c55e105
3 changed files with 33 additions and 13 deletions
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14
lib/rbcodec/codecs/libasf/asf.c
View file

@ -386,11 +386,17 @@ int asf_get_timestamp(int *duration)
int asf_seek(int ms, asf_waveformatex_t* wfx)
{
int time, duration, delta, temp, count=0;
int bitrate = ci->id3->bitrate*1000/8;
/*estimate packet number from bitrate*/
int initial_packet = ci->curpos/wfx->packet_size;
int packet_num = (((int64_t)ms)*(wfx->bitrate>>3))/wfx->packet_size/1000;
int last_packet = ci->id3->filesize / wfx->packet_size;
int packet_num = (((int64_t)ms)*(bitrate))/wfx->packet_size/1000;
/*subtract header size in case theres a lot of metadata*/
int last_packet = (ci->id3->filesize-ci->id3->first_frame_offset) / wfx->packet_size;
/*
DEBUGF("bitrate: %d\n", bitrate);
DEBUGF("attempting seek to: %d ms, initialp: %d, lastp: %d, estimating packet: %d, packet size: %d\n", ms, initial_packet, last_packet, packet_num, wfx->packet_size);*/
if (packet_num > last_packet) {
packet_num = last_packet;
@ -409,7 +415,7 @@ int asf_seek(int ms, asf_waveformatex_t* wfx)
/*check the time stamp of our packet*/
time = asf_get_timestamp(&duration);
/*DEBUGF("seeked to %d ms with duration %d\n", time, duration);*/
/*DEBUGF("seeked to %d ms (%d) with duration %d\n", time,packet_num, duration);*/
if (time < 0) {
/*unknown error, try to recover*/
@ -427,7 +433,7 @@ int asf_seek(int ms, asf_waveformatex_t* wfx)
delta = ms-time;
/*estimate new packet number from bitrate and our current position*/
temp += delta;
packet_num = ((temp/1000)*(wfx->bitrate>>3) - (wfx->packet_size>>1))/wfx->packet_size; //round down!
packet_num = ((temp/1000)*(bitrate) - (wfx->packet_size<<1))/wfx->packet_size; //round down!
packet_offset = packet_num*wfx->packet_size;
ci->seek_buffer(ci->id3->first_frame_offset+packet_offset);
}

2
lib/rbcodec/codecs/libasf/asf.h
View file

@ -33,7 +33,7 @@ struct asf_waveformatex_s {
uint16_t blockalign;
uint16_t bitspersample;
uint16_t datalen;
uint16_t numpackets;
uint64_t numpackets;
uint8_t data[46];
};
typedef struct asf_waveformatex_s asf_waveformatex_t;