Author: ods15 Date: Sat Nov 18 19:33:58 2006 New Revision: 247 Modified: trunk/libnut/demuxer.c Log: Add backwards ability to smart_find_syncpoint, for backwards seeks Modified: trunk/libnut/demuxer.c ============================================================================== --- trunk/libnut/demuxer.c (original) +++ trunk/libnut/demuxer.c Sat Nov 18 19:33:58 2006 @@ -837,20 +837,20 @@ return err; } -static int smart_find_syncpoint(nut_context_t * nut, syncpoint_t * sp) { +static int smart_find_syncpoint(nut_context_t * nut, syncpoint_t * sp, int backwards) { struct find_syncpoint_state_s * fss = &nut->find_syncpoint_state; syncpoint_list_t * sl = &nut->syncpoints; int i = fss->i, err = 0; - off_t pos = i ? fss->pos : bctello(nut->i); + off_t pos = fss->i ? fss->pos : bctello(nut->i); if (!(nut->dopts.cache_syncpoints & 1) || !sl->len) return find_syncpoint(nut, 0, sp, 0); if (!i) { for (i = 0; i < sl->len; i++) if (sl->s[i].pos+15 > pos) break; - if (i && !sl->s[i-1].seen_next) return find_syncpoint(nut, 0, sp, 0); + if (i == sl->len || (i && !sl->s[i-1].seen_next)) return find_syncpoint(nut, 0, sp, 0); seek_buf(nut->i, sl->s[i].pos, SEEK_SET); - } + } else i--; fss->i = i + 1; fss->pos = pos; @@ -860,23 +860,32 @@ if (sp->seen_next) { // failure int j, begin = fss->begin ? fss->begin - 1 : i; fss->begin = begin + 1; - while (sl->s[i].seen_next) { - if (!fss->seeked) seek_buf(nut->i, sl->s[i+1].pos, SEEK_SET); + while (i < backwards*2 || sl->s[i-backwards*2].seen_next) { + int o = backwards ? -1 : +1; + if (!fss->seeked) seek_buf(nut->i, sl->s[i+o].pos, SEEK_SET); fss->seeked = 1; - CHECK(find_syncpoint(nut, 0, sp, sl->s[i+1].pos + 15 + 8)); + CHECK(find_syncpoint(nut, 0, sp, sl->s[i+o].pos + 15 + 8)); fss->seeked = 0; - fss->i = ++i + 1; - if (!sp->seen_next) break; + fss->i = (i+=o) + 1; + if (!sp->seen_next || !i) break; } if (sp->seen_next) { // still nothing! let's linear search the whole area - if (!fss->seeked) seek_buf(nut->i, begin > 0 ? sl->s[begin-1].pos+15 : 0, SEEK_SET); + if (!fss->seeked) { + if (backwards) seek_buf(nut->i, sl->s[begin].pos - nut->max_distance, SEEK_SET); + else seek_buf(nut->i, begin > 0 ? sl->s[begin-1].pos+15 : 0, SEEK_SET); + } fss->seeked = 1; - CHECK(find_syncpoint(nut, 0, sp, 0)); + CHECK(find_syncpoint(nut, backwards, sp, 0)); fss->seeked = 0; } CHECK(add_syncpoint(nut, *sp, NULL, NULL, &i)); - assert(i >= begin); + assert((i >= begin && !backwards) || (i <= begin && backwards)); + if (backwards) { // swap vars + int tmp = begin; + begin = i + 1; + i = tmp + 1; + } sl->s[i].pts_valid = 0; sl->s[i].seen_next = 0; for (j = 0; j < nut->stream_count; j++) { @@ -890,10 +899,10 @@ sl->len -= i-begin; - if (sp->pos < pos) { // wow, how silly! + if (sp->pos < pos && !backwards) { // wow, how silly! fss->pos = fss->i = fss->begin = fss->seeked = 0; seek_buf(nut->i, pos, SEEK_SET); - return smart_find_syncpoint(nut, sp); + return smart_find_syncpoint(nut, sp, backwards); } } fss->pos = fss->i = fss->begin = fss->seeked = 0; @@ -906,7 +915,7 @@ int err = 0; if (nut->seek_status) { // in error mode! syncpoint_t s; - CHECK(smart_find_syncpoint(nut, &s)); + CHECK(smart_find_syncpoint(nut, &s, 0)); nut->i->buf_ptr = get_buf(nut->i, s.pos); // go back to begginning of syncpoint flush_buf(nut->i); clear_dts_cache(nut); @@ -918,8 +927,8 @@ if (err > NUT_ERR_OUT_OF_MEM) { // some error occured! fprintf(stderr, "NUT: %s\n", nut_error(err)); // rewind as much as possible - if (nut->i->isc.seek) seek_buf(nut->i, nut->last_syncpoint + 8, SEEK_SET); - else nut->i->buf_ptr = nut->i->buf; + if (nut->i->isc.seek) seek_buf(nut->i, nut->last_syncpoint + 16, SEEK_SET); + else nut->i->buf_ptr = nut->i->buf + MIN(16, nut->i->read_len); nut->seek_status = 1; // enter error mode return nut_read_next_packet(nut, pd); @@ -1021,7 +1030,7 @@ seek_buf(nut->i, 0, SEEK_SET); nut->seek_status = 1; } - CHECK(smart_find_syncpoint(nut, &sp)); + CHECK(smart_find_syncpoint(nut, &sp, 0)); CHECK(add_syncpoint(nut, sp, NULL, NULL, NULL)); nut->i->buf_ptr = get_buf(nut->i, sp.pos); // rewind to the syncpoint, this is where playback starts... nut->seek_status = 0; @@ -1162,8 +1171,7 @@ if (!nut->seek_status) seek_buf(nut->i, start, SEEK_SET); nut->seek_status = 1; // find closest syncpoint by linear search, SHOULD be one pointed by back_ptr... - buf_before = bctello(nut->i); - CHECK(smart_find_syncpoint(nut, &s)); + CHECK(smart_find_syncpoint(nut, &s, !!end)); clear_dts_cache(nut); nut->last_syncpoint = 0; // last_key is invalid seek_buf(nut->i, s.pos, SEEK_SET); // go back to syncpoint. This will not need a seek. @@ -1294,10 +1302,8 @@ clear_dts_cache(nut); } nut->seek_status = 0; - } else if (buf_before) { - if (buf_before >= nut->i->file_pos) nut->i->buf_ptr = get_buf(nut->i, buf_before); // rewind - else nut->i->buf_ptr = nut->i->buf; // special case, possible with smart_/find_syncpoint - } + } else if (buf_before) nut->i->buf_ptr = get_buf(nut->i, buf_before); // rewind smart + else nut->i->buf_ptr = nut->i->buf; // just rewind return err; }