mirror of https://git.ffmpeg.org/ffmpeg.git
458 lines
15 KiB
C
458 lines
15 KiB
C
/*
|
|
* 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"
|
|
|
|
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;
|
|
|
|
track->rtp_ctx = ff_rtp_chain_mux_open(s, src_st, NULL,
|
|
RTP_MAX_PACKET_SIZE);
|
|
if (!track->rtp_ctx)
|
|
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, AVPacket *pkt, int sample)
|
|
{
|
|
/* No need to keep track of smaller samples, since describing them
|
|
* with immediates is more efficient. */
|
|
if (pkt->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 = pkt->data;
|
|
queue->samples[queue->len].size = pkt->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 (data[1] >= 200 && data[1] <= 204) {
|
|
/* 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)
|
|
{
|
|
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);
|
|
|
|
sample_queue_push(&trk->sample_queue, pkt, 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);
|
|
}
|
|
|