| /* | |
| * MOV, 3GP, MP4 muxer RTP hinting | |
| * Copyright (c) 2010 Martin Storsjo | |
| * | |
| * This file is part of FFmpeg. | |
| * | |
| * FFmpeg 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. | |
| * | |
| * FFmpeg 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 FFmpeg; if not, write to the Free Software | |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
| */ | |
| #include "movenc.h" | |
| #include "libavutil/intreadwrite.h" | |
| #include "mux.h" | |
| #include "rtpenc_chain.h" | |
| #include "avio_internal.h" | |
| #include "rtp.h" | |
| int ff_mov_init_hinting(AVFormatContext *s, int index, int src_index) | |
| { | |
| MOVMuxContext *mov = s->priv_data; | |
| MOVTrack *track = &mov->tracks[index]; | |
| MOVTrack *src_track = &mov->tracks[src_index]; | |
| AVStream *src_st = s->streams[src_index]; | |
| int ret = AVERROR(ENOMEM); | |
| track->tag = MKTAG('r','t','p',' '); | |
| track->src_track = src_index; | |
| track->par = avcodec_parameters_alloc(); | |
| if (!track->par) | |
| goto fail; | |
| track->par->codec_type = AVMEDIA_TYPE_DATA; | |
| track->par->codec_tag = track->tag; | |
| ret = ff_rtp_chain_mux_open(&track->rtp_ctx, s, src_st, NULL, | |
| RTP_MAX_PACKET_SIZE, src_index); | |
| if (ret < 0) | |
| goto fail; | |
| /* Copy the RTP AVStream timebase back to the hint AVStream */ | |
| track->timescale = track->rtp_ctx->streams[0]->time_base.den; | |
| /* Mark the hinted track that packets written to it should be | |
| * sent to this track for hinting. */ | |
| src_track->hint_track = index; | |
| return 0; | |
| fail: | |
| av_log(s, AV_LOG_WARNING, | |
| "Unable to initialize hinting of stream %d\n", src_index); | |
| avcodec_parameters_free(&track->par); | |
| /* Set a default timescale, to avoid crashes in av_dump_format */ | |
| track->timescale = 90000; | |
| return ret; | |
| } | |
| /** | |
| * Remove the first sample from the sample queue. | |
| */ | |
| static void sample_queue_pop(HintSampleQueue *queue) | |
| { | |
| if (queue->len <= 0) | |
| return; | |
| if (queue->samples[0].own_data) | |
| av_freep(&queue->samples[0].data); | |
| queue->len--; | |
| memmove(queue->samples, queue->samples + 1, sizeof(HintSample)*queue->len); | |
| } | |
| /** | |
| * Empty the sample queue, releasing all memory. | |
| */ | |
| static void sample_queue_free(HintSampleQueue *queue) | |
| { | |
| int i; | |
| for (i = 0; i < queue->len; i++) | |
| if (queue->samples[i].own_data) | |
| av_freep(&queue->samples[i].data); | |
| av_freep(&queue->samples); | |
| queue->len = 0; | |
| queue->size = 0; | |
| } | |
| /** | |
| * Add a reference to the sample data to the sample queue. The data is | |
| * not copied. sample_queue_retain should be called before pkt->data | |
| * is reused/freed. | |
| */ | |
| static void sample_queue_push(HintSampleQueue *queue, const uint8_t *data, int size, | |
| int sample) | |
| { | |
| /* No need to keep track of smaller samples, since describing them | |
| * with immediates is more efficient. */ | |
| if (size <= 14) | |
| return; | |
| if (!queue->samples || queue->len >= queue->size) { | |
| HintSample *samples; | |
| samples = av_realloc_array(queue->samples, queue->size + 10, sizeof(HintSample)); | |
| if (!samples) | |
| return; | |
| queue->size += 10; | |
| queue->samples = samples; | |
| } | |
| queue->samples[queue->len].data = data; | |
| queue->samples[queue->len].size = size; | |
| queue->samples[queue->len].sample_number = sample; | |
| queue->samples[queue->len].offset = 0; | |
| queue->samples[queue->len].own_data = 0; | |
| queue->len++; | |
| } | |
| /** | |
| * Make local copies of all referenced sample data in the queue. | |
| */ | |
| static void sample_queue_retain(HintSampleQueue *queue) | |
| { | |
| int i; | |
| for (i = 0; i < queue->len; ) { | |
| HintSample *sample = &queue->samples[i]; | |
| if (!sample->own_data) { | |
| uint8_t *ptr = av_malloc(sample->size); | |
| if (!ptr) { | |
| /* Unable to allocate memory for this one, remove it */ | |
| memmove(queue->samples + i, queue->samples + i + 1, | |
| sizeof(HintSample)*(queue->len - i - 1)); | |
| queue->len--; | |
| continue; | |
| } | |
| memcpy(ptr, sample->data, sample->size); | |
| sample->data = ptr; | |
| sample->own_data = 1; | |
| } | |
| i++; | |
| } | |
| } | |
| /** | |
| * Find matches of needle[n_pos ->] within haystack. If a sufficiently | |
| * large match is found, matching bytes before n_pos are included | |
| * in the match, too (within the limits of the arrays). | |
| * | |
| * @param haystack buffer that may contain parts of needle | |
| * @param h_len length of the haystack buffer | |
| * @param needle buffer containing source data that have been used to | |
| * construct haystack | |
| * @param n_pos start position in needle used for looking for matches | |
| * @param n_len length of the needle buffer | |
| * @param match_h_offset_ptr offset of the first matching byte within haystack | |
| * @param match_n_offset_ptr offset of the first matching byte within needle | |
| * @param match_len_ptr length of the matched segment | |
| * @return 0 if a match was found, < 0 if no match was found | |
| */ | |
| static int match_segments(const uint8_t *haystack, int h_len, | |
| const uint8_t *needle, int n_pos, int n_len, | |
| int *match_h_offset_ptr, int *match_n_offset_ptr, | |
| int *match_len_ptr) | |
| { | |
| int h_pos; | |
| for (h_pos = 0; h_pos < h_len; h_pos++) { | |
| int match_len = 0; | |
| int match_h_pos, match_n_pos; | |
| /* Check how many bytes match at needle[n_pos] and haystack[h_pos] */ | |
| while (h_pos + match_len < h_len && n_pos + match_len < n_len && | |
| needle[n_pos + match_len] == haystack[h_pos + match_len]) | |
| match_len++; | |
| if (match_len <= 8) | |
| continue; | |
| /* If a sufficiently large match was found, try to expand | |
| * the matched segment backwards. */ | |
| match_h_pos = h_pos; | |
| match_n_pos = n_pos; | |
| while (match_n_pos > 0 && match_h_pos > 0 && | |
| needle[match_n_pos - 1] == haystack[match_h_pos - 1]) { | |
| match_n_pos--; | |
| match_h_pos--; | |
| match_len++; | |
| } | |
| if (match_len <= 14) | |
| continue; | |
| *match_h_offset_ptr = match_h_pos; | |
| *match_n_offset_ptr = match_n_pos; | |
| *match_len_ptr = match_len; | |
| return 0; | |
| } | |
| return -1; | |
| } | |
| /** | |
| * Look for segments in samples in the sample queue matching the data | |
| * in ptr. Samples not matching are removed from the queue. If a match | |
| * is found, the next time it will look for matches starting from the | |
| * end of the previous matched segment. | |
| * | |
| * @param data data to find matches for in the sample queue | |
| * @param len length of the data buffer | |
| * @param queue samples used for looking for matching segments | |
| * @param pos the offset in data of the matched segment | |
| * @param match_sample the number of the sample that contained the match | |
| * @param match_offset the offset of the matched segment within the sample | |
| * @param match_len the length of the matched segment | |
| * @return 0 if a match was found, < 0 if no match was found | |
| */ | |
| static int find_sample_match(const uint8_t *data, int len, | |
| HintSampleQueue *queue, int *pos, | |
| int *match_sample, int *match_offset, | |
| int *match_len) | |
| { | |
| while (queue->len > 0) { | |
| HintSample *sample = &queue->samples[0]; | |
| /* If looking for matches in a new sample, skip the first 5 bytes, | |
| * since they often may be modified/removed in the output packet. */ | |
| if (sample->offset == 0 && sample->size > 5) | |
| sample->offset = 5; | |
| if (match_segments(data, len, sample->data, sample->offset, | |
| sample->size, pos, match_offset, match_len) == 0) { | |
| *match_sample = sample->sample_number; | |
| /* Next time, look for matches at this offset, with a little | |
| * margin to this match. */ | |
| sample->offset = *match_offset + *match_len + 5; | |
| if (sample->offset + 10 >= sample->size) | |
| sample_queue_pop(queue); /* Not enough useful data left */ | |
| return 0; | |
| } | |
| if (sample->offset < 10 && sample->size > 20) { | |
| /* No match found from the start of the sample, | |
| * try from the middle of the sample instead. */ | |
| sample->offset = sample->size/2; | |
| } else { | |
| /* No match for this sample, remove it */ | |
| sample_queue_pop(queue); | |
| } | |
| } | |
| return -1; | |
| } | |
| static void output_immediate(const uint8_t *data, int size, | |
| AVIOContext *out, int *entries) | |
| { | |
| while (size > 0) { | |
| int len = size; | |
| if (len > 14) | |
| len = 14; | |
| avio_w8(out, 1); /* immediate constructor */ | |
| avio_w8(out, len); /* amount of valid data */ | |
| avio_write(out, data, len); | |
| data += len; | |
| size -= len; | |
| ffio_fill(out, 0, 14 - len); | |
| (*entries)++; | |
| } | |
| } | |
| static void output_match(AVIOContext *out, int match_sample, | |
| int match_offset, int match_len, int *entries) | |
| { | |
| avio_w8(out, 2); /* sample constructor */ | |
| avio_w8(out, 0); /* track reference */ | |
| avio_wb16(out, match_len); | |
| avio_wb32(out, match_sample); | |
| avio_wb32(out, match_offset); | |
| avio_wb16(out, 1); /* bytes per block */ | |
| avio_wb16(out, 1); /* samples per block */ | |
| (*entries)++; | |
| } | |
| static void describe_payload(const uint8_t *data, int size, | |
| AVIOContext *out, int *entries, | |
| HintSampleQueue *queue) | |
| { | |
| /* Describe the payload using different constructors */ | |
| while (size > 0) { | |
| int match_sample, match_offset, match_len, pos; | |
| if (find_sample_match(data, size, queue, &pos, &match_sample, | |
| &match_offset, &match_len) < 0) | |
| break; | |
| output_immediate(data, pos, out, entries); | |
| data += pos; | |
| size -= pos; | |
| output_match(out, match_sample, match_offset, match_len, entries); | |
| data += match_len; | |
| size -= match_len; | |
| } | |
| output_immediate(data, size, out, entries); | |
| } | |
| /** | |
| * Write an RTP hint (that may contain one or more RTP packets) | |
| * for the packets in data. data contains one or more packets with a | |
| * BE32 size header. | |
| * | |
| * @param out buffer where the hints are written | |
| * @param data buffer containing RTP packets | |
| * @param size the size of the data buffer | |
| * @param trk the MOVTrack for the hint track | |
| * @param dts pointer where the timestamp for the written RTP hint is stored | |
| * @return the number of RTP packets in the written hint | |
| */ | |
| static int write_hint_packets(AVIOContext *out, const uint8_t *data, | |
| int size, MOVTrack *trk, int64_t *dts) | |
| { | |
| int64_t curpos; | |
| int64_t count_pos, entries_pos; | |
| int count = 0, entries; | |
| count_pos = avio_tell(out); | |
| /* RTPsample header */ | |
| avio_wb16(out, 0); /* packet count */ | |
| avio_wb16(out, 0); /* reserved */ | |
| while (size > 4) { | |
| uint32_t packet_len = AV_RB32(data); | |
| uint16_t seq; | |
| uint32_t ts; | |
| int32_t ts_diff; | |
| data += 4; | |
| size -= 4; | |
| if (packet_len > size || packet_len <= 12) | |
| break; | |
| if (RTP_PT_IS_RTCP(data[1])) { | |
| /* RTCP packet, just skip */ | |
| data += packet_len; | |
| size -= packet_len; | |
| continue; | |
| } | |
| if (packet_len > trk->max_packet_size) | |
| trk->max_packet_size = packet_len; | |
| seq = AV_RB16(&data[2]); | |
| ts = AV_RB32(&data[4]); | |
| if (trk->prev_rtp_ts == 0) | |
| trk->prev_rtp_ts = ts; | |
| /* Unwrap the 32-bit RTP timestamp that wraps around often | |
| * into a not (as often) wrapping 64-bit timestamp. */ | |
| ts_diff = ts - trk->prev_rtp_ts; | |
| if (ts_diff > 0) { | |
| trk->cur_rtp_ts_unwrapped += ts_diff; | |
| trk->prev_rtp_ts = ts; | |
| ts_diff = 0; | |
| } | |
| if (*dts == AV_NOPTS_VALUE) | |
| *dts = trk->cur_rtp_ts_unwrapped; | |
| count++; | |
| /* RTPpacket header */ | |
| avio_wb32(out, 0); /* relative_time */ | |
| avio_write(out, data, 2); /* RTP header */ | |
| avio_wb16(out, seq); /* RTPsequenceseed */ | |
| avio_wb16(out, ts_diff ? 4 : 0); /* reserved + flags (extra_flag) */ | |
| entries_pos = avio_tell(out); | |
| avio_wb16(out, 0); /* entry count */ | |
| if (ts_diff) { /* if extra_flag is set */ | |
| avio_wb32(out, 16); /* extra_information_length */ | |
| avio_wb32(out, 12); /* rtpoffsetTLV box */ | |
| avio_write(out, "rtpo", 4); | |
| avio_wb32(out, ts_diff); | |
| } | |
| data += 12; | |
| size -= 12; | |
| packet_len -= 12; | |
| entries = 0; | |
| /* Write one or more constructors describing the payload data */ | |
| describe_payload(data, packet_len, out, &entries, &trk->sample_queue); | |
| data += packet_len; | |
| size -= packet_len; | |
| curpos = avio_tell(out); | |
| avio_seek(out, entries_pos, SEEK_SET); | |
| avio_wb16(out, entries); | |
| avio_seek(out, curpos, SEEK_SET); | |
| } | |
| curpos = avio_tell(out); | |
| avio_seek(out, count_pos, SEEK_SET); | |
| avio_wb16(out, count); | |
| avio_seek(out, curpos, SEEK_SET); | |
| return count; | |
| } | |
| int ff_mov_add_hinted_packet(AVFormatContext *s, AVPacket *pkt, | |
| int track_index, int sample, | |
| uint8_t *sample_data, int sample_size) | |
| { | |
| MOVMuxContext *mov = s->priv_data; | |
| MOVTrack *trk = &mov->tracks[track_index]; | |
| AVFormatContext *rtp_ctx = trk->rtp_ctx; | |
| uint8_t *buf = NULL; | |
| int size; | |
| AVIOContext *hintbuf = NULL; | |
| AVPacket *hint_pkt = mov->pkt; | |
| int ret = 0, count; | |
| if (!rtp_ctx) | |
| return AVERROR(ENOENT); | |
| if (!rtp_ctx->pb) | |
| return AVERROR(ENOMEM); | |
| if (sample_data) | |
| sample_queue_push(&trk->sample_queue, sample_data, sample_size, sample); | |
| else | |
| sample_queue_push(&trk->sample_queue, pkt->data, pkt->size, sample); | |
| /* Feed the packet to the RTP muxer */ | |
| ff_write_chained(rtp_ctx, 0, pkt, s, 0); | |
| /* Fetch the output from the RTP muxer, open a new output buffer | |
| * for next time. */ | |
| size = avio_close_dyn_buf(rtp_ctx->pb, &buf); | |
| if ((ret = ffio_open_dyn_packet_buf(&rtp_ctx->pb, | |
| RTP_MAX_PACKET_SIZE)) < 0) | |
| goto done; | |
| if (size <= 0) | |
| goto done; | |
| /* Open a buffer for writing the hint */ | |
| if ((ret = avio_open_dyn_buf(&hintbuf)) < 0) | |
| goto done; | |
| av_packet_unref(hint_pkt); | |
| count = write_hint_packets(hintbuf, buf, size, trk, &hint_pkt->dts); | |
| av_freep(&buf); | |
| /* Write the hint data into the hint track */ | |
| hint_pkt->size = size = avio_close_dyn_buf(hintbuf, &buf); | |
| hint_pkt->data = buf; | |
| hint_pkt->pts = hint_pkt->dts; | |
| hint_pkt->stream_index = track_index; | |
| if (pkt->flags & AV_PKT_FLAG_KEY) | |
| hint_pkt->flags |= AV_PKT_FLAG_KEY; | |
| if (count > 0) | |
| ff_mov_write_packet(s, hint_pkt); | |
| done: | |
| av_free(buf); | |
| av_packet_unref(hint_pkt); | |
| sample_queue_retain(&trk->sample_queue); | |
| return ret; | |
| } | |
| void ff_mov_close_hinting(MOVTrack *track) | |
| { | |
| AVFormatContext *rtp_ctx = track->rtp_ctx; | |
| avcodec_parameters_free(&track->par); | |
| sample_queue_free(&track->sample_queue); | |
| if (!rtp_ctx) | |
| return; | |
| if (rtp_ctx->pb) { | |
| av_write_trailer(rtp_ctx); | |
| ffio_free_dyn_buf(&rtp_ctx->pb); | |
| } | |
| avformat_free_context(rtp_ctx); | |
| } |