making act segmenter

1 files changed, 462 insertions, 0 deletions

diff --git a/ffmpeg/libavformat/movenchint.c b/ffmpeg/libavformat/movenchint.c
new file mode 100644
index 0000000..cc90f0b
--- /dev/null
+++ b/ffmpeg/libavformat/movenchint.c
@@ -0,0 +1,462 @@
+/*
+ * 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 "internal.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->enc = avcodec_alloc_context3(NULL);
+    if (!track->enc)
+        goto fail;
+    track->enc->codec_type = AVMEDIA_TYPE_DATA;
+    track->enc->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);
+    av_freep(&track->enc);
+    /* 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_free(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_free(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, 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;
+        queue->size += 10;
+        samples = av_realloc(queue->samples, sizeof(HintSample)*queue->size);
+        if (!samples)
+            return;
+        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;
+
+        for (; len < 14; len++)
+            avio_w8(out, 0);
+
+        (*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 pts 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 *pts)
+{
+    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;
+
+        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. */
+        trk->cur_rtp_ts_unwrapped += (int32_t) (ts - trk->prev_rtp_ts);
+        trk->prev_rtp_ts = ts;
+        if (*pts == AV_NOPTS_VALUE)
+            *pts = 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, 0); /* reserved + flags */
+        entries_pos = avio_tell(out);
+        avio_wb16(out, 0); /* entry count */
+
+        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;
+    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);
+
+    /* 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_init_packet(&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);
+    sample_queue_retain(&trk->sample_queue);
+    return ret;
+}
+
+void ff_mov_close_hinting(MOVTrack *track) {
+    AVFormatContext* rtp_ctx = track->rtp_ctx;
+    uint8_t *ptr;
+
+    av_freep(&track->enc);
+    sample_queue_free(&track->sample_queue);
+    if (!rtp_ctx)
+        return;
+    if (rtp_ctx->pb) {
+        av_write_trailer(rtp_ctx);
+        avio_close_dyn_buf(rtp_ctx->pb, &ptr);
+        av_free(ptr);
+    }
+    avformat_free_context(rtp_ctx);
+}