/* * This file is part of mpv. * * mpv is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * mpv is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with mpv. If not, see . */ #include #include #include #include #include #include #include "config.h" #include "common/av_common.h" #include "common/common.h" #include "demux.h" #include "packet.h" // Free any refcounted data dp holds (but don't free dp itself). This does not // care about pointers that are _not_ refcounted (like demux_packet.codec). // Normally, a user should use talloc_free(dp). This function is only for // annoyingly specific obscure use cases. void demux_packet_unref_contents(struct demux_packet *dp) { if (dp->avpacket) { assert(!dp->is_cached); av_packet_free(&dp->avpacket); dp->buffer = NULL; dp->len = 0; } } static void packet_destroy(void *ptr) { struct demux_packet *dp = ptr; demux_packet_unref_contents(dp); } // This actually preserves only data and side data, not PTS/DTS/pos/etc. // It also allows avpkt->data==NULL with avpkt->size!=0 - the libavcodec API // does not allow it, but we do it to simplify new_demux_packet(). struct demux_packet *new_demux_packet_from_avpacket(struct AVPacket *avpkt) { if (avpkt->size > 1000000000) return NULL; struct demux_packet *dp = talloc(NULL, struct demux_packet); talloc_set_destructor(dp, packet_destroy); *dp = (struct demux_packet) { .pts = MP_NOPTS_VALUE, .dts = MP_NOPTS_VALUE, .duration = -1, .pos = -1, .start = MP_NOPTS_VALUE, .end = MP_NOPTS_VALUE, .stream = -1, .avpacket = av_packet_alloc(), }; int r = -1; if (!dp->avpacket) { // error } else if (avpkt->data) { // We hope that this function won't need/access AVPacket input padding, // because otherwise new_demux_packet_from() wouldn't work. r = av_packet_ref(dp->avpacket, avpkt); } else { r = av_new_packet(dp->avpacket, avpkt->size); } if (r < 0) { talloc_free(dp); return NULL; } dp->buffer = dp->avpacket->data; dp->len = dp->avpacket->size; return dp; } // (buf must include proper padding) struct demux_packet *new_demux_packet_from_buf(struct AVBufferRef *buf) { if (!buf) return NULL; AVPacket pkt = { .size = buf->size, .data = buf->data, .buf = buf, }; return new_demux_packet_from_avpacket(&pkt); } // Input data doesn't need to be padded. struct demux_packet *new_demux_packet_from(void *data, size_t len) { if (len > INT_MAX) return NULL; AVPacket pkt = { .data = data, .size = len }; return new_demux_packet_from_avpacket(&pkt); } struct demux_packet *new_demux_packet(size_t len) { if (len > INT_MAX) return NULL; AVPacket pkt = { .data = NULL, .size = len }; return new_demux_packet_from_avpacket(&pkt); } void demux_packet_shorten(struct demux_packet *dp, size_t len) { assert(len <= dp->len); if (dp->len) { dp->len = len; memset(dp->buffer + dp->len, 0, AV_INPUT_BUFFER_PADDING_SIZE); } } void free_demux_packet(struct demux_packet *dp) { talloc_free(dp); } void demux_packet_copy_attribs(struct demux_packet *dst, struct demux_packet *src) { dst->pts = src->pts; dst->dts = src->dts; dst->duration = src->duration; dst->pos = src->pos; dst->segmented = src->segmented; dst->start = src->start; dst->end = src->end; dst->codec = src->codec; dst->back_restart = src->back_restart; dst->back_preroll = src->back_preroll; dst->keyframe = src->keyframe; dst->stream = src->stream; } struct demux_packet *demux_copy_packet(struct demux_packet *dp) { struct demux_packet *new = NULL; if (dp->avpacket) { new = new_demux_packet_from_avpacket(dp->avpacket); } else { // Some packets might be not created by new_demux_packet*(). new = new_demux_packet_from(dp->buffer, dp->len); } if (!new) return NULL; demux_packet_copy_attribs(new, dp); return new; } #define ROUND_ALLOC(s) MP_ALIGN_UP((s), 16) // Attempt to estimate the total memory consumption of the given packet. // This is important if we store thousands of packets and not to exceed // user-provided limits. Of course we can't know how much memory internal // fragmentation of the libc memory allocator will waste. // Note that this should return a "stable" value - e.g. if a new packet ref // is created, this should return the same value with the new ref. (This // implies the value is not exact and does not return the actual size of // memory wasted due to internal fragmentation.) size_t demux_packet_estimate_total_size(struct demux_packet *dp) { size_t size = ROUND_ALLOC(sizeof(struct demux_packet)); size += 8 * sizeof(void *); // ta overhead size += 10 * sizeof(void *); // additional estimate for ta_ext_header if (dp->avpacket) { assert(!dp->is_cached); size += ROUND_ALLOC(dp->len); size += ROUND_ALLOC(sizeof(AVPacket)); size += 8 * sizeof(void *); // ta overhead size += ROUND_ALLOC(sizeof(AVBufferRef)); size += ROUND_ALLOC(64); // upper bound estimate on sizeof(AVBuffer) size += ROUND_ALLOC(dp->avpacket->side_data_elems * sizeof(dp->avpacket->side_data[0])); for (int n = 0; n < dp->avpacket->side_data_elems; n++) size += ROUND_ALLOC(dp->avpacket->side_data[n].size); } return size; } int demux_packet_set_padding(struct demux_packet *dp, int start, int end) { if (!start && !end) return 0; if (!dp->avpacket) return -1; uint8_t *p = av_packet_new_side_data(dp->avpacket, AV_PKT_DATA_SKIP_SAMPLES, 10); if (!p) return -1; AV_WL32(p + 0, start); AV_WL32(p + 4, end); return 0; } int demux_packet_add_blockadditional(struct demux_packet *dp, uint64_t id, void *data, size_t size) { if (!dp->avpacket) return -1; uint8_t *sd = av_packet_new_side_data(dp->avpacket, AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL, 8 + size); if (!sd) return -1; AV_WB64(sd, id); if (size > 0) memcpy(sd + 8, data, size); return 0; }