diff options
| -rw-r--r-- | demux/demux.c | 98 |
1 files changed, 72 insertions, 26 deletions
diff --git a/demux/demux.c b/demux/demux.c index 82d28cf541..3032e69784 100644 --- a/demux/demux.c +++ b/demux/demux.c @@ -269,7 +269,25 @@ struct demux_cached_range { bool is_eof; // set if the file ends with this range }; -#define MAX_INDEX_ENTRIES 16 +#define QUEUE_INDEX_SIZE_MASK(queue) ((queue)->index_size - 1) + +// Access the idx-th entry in the given demux_queue. +// Requirement: idx >= 0 && idx < queue->num_index +#define QUEUE_INDEX_ENTRY(queue, idx) \ + ((queue)->index[((queue)->index0 + (idx)) & QUEUE_INDEX_SIZE_MASK(queue)]) + +// Don't index packets whose timestamps that are within the last index entry by +// this amount of time (it's better to seek them manually). +#define INDEX_STEP_SIZE 1.0 + +// Approximate worst case number of bytes a keyframe packet uses for the index. +// (Worst case: every KF packet is indexed; index buffer is overallocated.) +#define KF_SEEK_ENTRY_WORST_CASE (sizeof(struct index_entry) * 2) + +struct index_entry { + double pts; + struct demux_packet *pkt; +}; // A continuous list of cached packets for a single stream/range. There is one // for each stream and range. Also contains some state for use during demuxing @@ -302,11 +320,11 @@ struct demux_queue { bool is_bof; // started demuxing at beginning of file bool is_eof; // received true EOF here - // incomplete index to somewhat speed up seek operations - // the entries in index[] must be in packet queue append/removal order - int num_index; // valid index[] entries - double index_distance; // minimum keyframe distance to add index element - struct demux_packet *index[MAX_INDEX_ENTRIES]; + // Complete index, though it may skip some entries to reduce density. + struct index_entry *index; // ring buffer + size_t index_size; // size of index[] (0 or a power of 2) + size_t index0; // first index entry + size_t num_index; // number of index entries (wraps on index_size) }; struct demux_stream { @@ -431,7 +449,7 @@ static void check_queue_consistency(struct demux_internal *in) bool is_forward = false; bool kf_found = false; bool npt_found = false; - int next_index = 0; + size_t next_index = 0; uint64_t queue_total_bytes = 0; for (struct demux_packet *dp = queue->head; dp; dp = dp->next) { is_forward |= dp == queue->ds->reader_head; @@ -439,6 +457,8 @@ static void check_queue_consistency(struct demux_internal *in) npt_found |= dp == queue->next_prune_target; size_t bytes = demux_packet_estimate_total_size(dp); + if (dp->keyframe) + bytes += KF_SEEK_ENTRY_WORST_CASE; total_bytes += bytes; queue_total_bytes += bytes; if (is_forward) { @@ -451,7 +471,8 @@ static void check_queue_consistency(struct demux_internal *in) if (!dp->next) assert(queue->tail == dp); - if (next_index < queue->num_index && queue->index[next_index] == dp) + if (next_index < queue->num_index && + QUEUE_INDEX_ENTRY(queue, next_index).pkt == dp) next_index += 1; } if (!queue->head) @@ -661,8 +682,10 @@ static void remove_head_packet(struct demux_queue *queue) uint64_t end_pos = dp->next ? dp->next->cum_pos : queue->tail_cum_pos; queue->ds->in->total_bytes -= end_pos - dp->cum_pos; - if (queue->num_index && queue->index[0] == dp) - MP_TARRAY_REMOVE_AT(queue->index, queue->num_index, 0); + if (queue->num_index && queue->index[queue->index0].pkt == dp) { + queue->index0 = (queue->index0 + 1) & QUEUE_INDEX_SIZE_MASK(queue); + queue->num_index -= 1; + } queue->head = dp->next; if (!queue->head) @@ -692,7 +715,6 @@ static void clear_queue(struct demux_queue *queue) queue->seek_start = queue->seek_end = queue->last_pruned = MP_NOPTS_VALUE; queue->num_index = 0; - queue->index_distance = 1.0; queue->correct_dts = queue->correct_pos = true; queue->last_pos = -1; @@ -1528,22 +1550,39 @@ static void back_demux_see_packets(struct demux_stream *ds) // Add the keyframe to the end of the index. Not all packets are actually added. static void add_index_entry(struct demux_queue *queue, struct demux_packet *dp) { + struct demux_internal *in = queue->ds->in; + assert(dp->keyframe && dp->kf_seek_pts != MP_NOPTS_VALUE); - if (queue->num_index) { - double prev = queue->index[queue->num_index - 1]->kf_seek_pts; - if (dp->kf_seek_pts < prev + queue->index_distance) + if (queue->num_index > 0) { + struct index_entry *last = &QUEUE_INDEX_ENTRY(queue, queue->num_index - 1); + if (dp->kf_seek_pts - last->pts < INDEX_STEP_SIZE) return; } - if (queue->num_index == MAX_INDEX_ENTRIES) { - for (int n = 0; n < MAX_INDEX_ENTRIES / 2; n++) - queue->index[n] = queue->index[n * 2]; - queue->num_index = MAX_INDEX_ENTRIES / 2; - queue->index_distance *= 2; + if (queue->num_index == queue->index_size) { + // Needs to honor power-of-2 requirement. + size_t new_size = MPMAX(128, queue->index_size * 2); + assert(!(new_size & (new_size - 1))); + MP_VERBOSE(in, "stream %d: resize index to %zu\n", queue->ds->index, + new_size); + // Note: we could tolerate allocation failure, and just discard the + // entire index (and prevent the index from being recreated). + MP_RESIZE_ARRAY(queue, queue->index, new_size); + size_t highest_index = queue->index0 + queue->num_index; + for (size_t n = queue->index_size; n < highest_index; n++) + queue->index[n] = queue->index[n - queue->index_size]; + queue->index_size = new_size; } - queue->index[queue->num_index++] = dp; + assert(queue->num_index < queue->index_size); + + queue->num_index += 1; + + QUEUE_INDEX_ENTRY(queue, queue->num_index - 1) = (struct index_entry){ + .pts = dp->kf_seek_pts, + .pkt = dp, + }; } // Check whether the next range in the list is, and if it appears to overlap, @@ -1689,10 +1728,10 @@ static void attempt_range_joining(struct demux_internal *in) q2->head = q2->tail = NULL; q2->next_prune_target = NULL; q2->keyframe_latest = NULL; - - for (int i = 0; i < q2->num_index; i++) - add_index_entry(q1, q2->index[i]); q2->num_index = 0; + q2->index_size = 0; + q2->index0 = 0; + TA_FREEP(&q2->index); if (ds->selected && !ds->reader_head) ds->reader_head = join_point; @@ -1704,6 +1743,10 @@ static void attempt_range_joining(struct demux_internal *in) uint64_t size = next_pos - dp->cum_pos; dp->cum_pos = q1->tail_cum_pos; q1->tail_cum_pos += size; + + // And update the index with packets from q2. + if (dp->keyframe && dp->kf_seek_pts != MP_NOPTS_VALUE) + add_index_entry(q1, dp); } // For moving demuxer position. @@ -1846,6 +1889,8 @@ static void add_packet_locked(struct sh_stream *stream, demux_packet_t *dp) } size_t bytes = demux_packet_estimate_total_size(dp); + if (dp->keyframe) + bytes += KF_SEEK_ENTRY_WORST_CASE; in->total_bytes += bytes; dp->cum_pos = queue->tail_cum_pos; queue->tail_cum_pos += bytes; @@ -3059,10 +3104,11 @@ static struct demux_packet *find_seek_target(struct demux_queue *queue, pts -= queue->ds->sh->seek_preroll; struct demux_packet *start = queue->head; - for (int n = 0; n < queue->num_index; n++) { - if (queue->index[n]->kf_seek_pts > pts) + for (size_t n = 0; n < queue->num_index; n++) { + struct index_entry *e = &QUEUE_INDEX_ENTRY(queue, n); + if (e->pts > pts) break; - start = queue->index[n]; + start = e->pkt; } struct demux_packet *target = NULL; |