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Refactor the 'fmt ' tag search and parsing

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Moving the search and parsing of the 'fmt ' info the main loop of wav_read_header() allows tags that precede it to be parsed.
Creating wav_parse_fmt_tag() makes wav_read_header() easier to read.
This commit is contained in:
Tomas Härdin 2011-05-17 19:46:08 +02:00 committed by Michael Niedermayer
parent a4b6000b00
commit cc1ca9e534
1 changed files with 39 additions and 18 deletions
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57
libavformat/wav.c
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@ -184,6 +184,26 @@ static int wav_probe(AVProbeData *p)
return 0;
}
static int wav_parse_fmt_tag(AVFormatContext *s, int64_t size, AVStream **st)
{
AVIOContext *pb = s->pb;
int ret;
/* parse fmt header */
*st = av_new_stream(s, 0);
if (!*st)
return AVERROR(ENOMEM);
ff_get_wav_header(pb, (*st)->codec, size);
if (ret < 0)
return ret;
(*st)->need_parsing = AVSTREAM_PARSE_FULL;
av_set_pts_info(*st, 64, 1, (*st)->codec->sample_rate);
return 0;
}
/* wav input */
static int wav_read_header(AVFormatContext *s,
AVFormatParameters *ap)
@ -195,7 +215,8 @@ static int wav_read_header(AVFormatContext *s,
AVIOContext *pb = s->pb;
AVStream *st;
WAVContext *wav = s->priv_data;
int ret;
int ret, got_fmt = 0;
int64_t next_tag_ofs;
/* check RIFF header */
tag = avio_rl32(pb);
@ -220,32 +241,32 @@ static int wav_read_header(AVFormatContext *s,
avio_skip(pb, size - 16); /* skip rest of ds64 chunk */
}
/* parse fmt header */
size = find_tag(pb, MKTAG('f', 'm', 't', ' '));
if (size < 0)
return -1;
st = av_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
ret = ff_get_wav_header(pb, st->codec, size);
if (ret < 0)
return ret;
st->need_parsing = AVSTREAM_PARSE_FULL;
av_set_pts_info(st, 64, 1, st->codec->sample_rate);
for (;;) {
if (url_feof(pb))
return -1;
size = next_tag(pb, &tag);
if (tag == MKTAG('d', 'a', 't', 'a')){
next_tag_ofs = url_ftell(pb) + size;
if (tag == MKTAG('f', 'm', 't', ' ')) {
/* only parse the first 'fmt ' tag found */
if (!got_fmt && (ret = wav_parse_fmt_tag(s, size, &st) < 0)) {
return ret;
} else if (got_fmt)
av_log(s, AV_LOG_WARNING, "found more than one 'fmt ' tag\n");
got_fmt = 1;
} else if (tag == MKTAG('d', 'a', 't', 'a')) {
if (!got_fmt) {
av_log(s, AV_LOG_ERROR, "found no 'fmt ' tag before the 'data' tag\n");
return AVERROR_INVALIDDATA;
}
break;
}else if (tag == MKTAG('f','a','c','t') && !sample_count){
sample_count = avio_rl32(pb);
size -= 4;
}
avio_skip(pb, size);
avio_seek(pb, next_tag_ofs, SEEK_SET);
}
if (rf64)
size = data_size;