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FFmpeg/libavformat/swfenc.c
2022-02-07 00:31:23 +01:00

578 lines
18 KiB
C

/*
* Flash Compatible Streaming Format muxer
* Copyright (c) 2000 Fabrice Bellard
* Copyright (c) 2003 Tinic Uro
*
* 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 "libavcodec/put_bits.h"
#include "libavutil/avassert.h"
#include "libavutil/fifo.h"
#include "avformat.h"
#include "flv.h"
#include "swf.h"
#define AUDIO_FIFO_SIZE 65536
typedef struct SWFEncContext {
int64_t duration_pos;
int64_t tag_pos;
int64_t vframes_pos;
int samples_per_frame;
int sound_samples;
int swf_frame_number;
int video_frame_number;
int tag;
AVFifo *audio_fifo;
AVCodecParameters *audio_par, *video_par;
AVStream *video_st;
} SWFEncContext;
static void put_swf_tag(AVFormatContext *s, int tag)
{
SWFEncContext *swf = s->priv_data;
AVIOContext *pb = s->pb;
swf->tag_pos = avio_tell(pb);
swf->tag = tag;
/* reserve some room for the tag */
if (tag & TAG_LONG) {
avio_wl16(pb, 0);
avio_wl32(pb, 0);
} else {
avio_wl16(pb, 0);
}
}
static void put_swf_end_tag(AVFormatContext *s)
{
SWFEncContext *swf = s->priv_data;
AVIOContext *pb = s->pb;
int64_t pos;
int tag_len, tag;
pos = avio_tell(pb);
tag_len = pos - swf->tag_pos - 2;
tag = swf->tag;
avio_seek(pb, swf->tag_pos, SEEK_SET);
if (tag & TAG_LONG) {
tag &= ~TAG_LONG;
avio_wl16(pb, (tag << 6) | 0x3f);
avio_wl32(pb, tag_len - 4);
} else {
av_assert0(tag_len < 0x3f);
avio_wl16(pb, (tag << 6) | tag_len);
}
avio_seek(pb, pos, SEEK_SET);
}
static inline void max_nbits(int *nbits_ptr, int val)
{
int n;
if (val == 0)
return;
val = FFABS(val);
n = 1;
while (val != 0) {
n++;
val >>= 1;
}
if (n > *nbits_ptr)
*nbits_ptr = n;
}
static void put_swf_rect(AVIOContext *pb,
int xmin, int xmax, int ymin, int ymax)
{
PutBitContext p;
uint8_t buf[256];
int nbits, mask;
init_put_bits(&p, buf, sizeof(buf));
nbits = 0;
max_nbits(&nbits, xmin);
max_nbits(&nbits, xmax);
max_nbits(&nbits, ymin);
max_nbits(&nbits, ymax);
mask = (1 << nbits) - 1;
/* rectangle info */
put_bits(&p, 5, nbits);
put_bits(&p, nbits, xmin & mask);
put_bits(&p, nbits, xmax & mask);
put_bits(&p, nbits, ymin & mask);
put_bits(&p, nbits, ymax & mask);
flush_put_bits(&p);
avio_write(pb, buf, put_bits_ptr(&p) - p.buf);
}
static void put_swf_line_edge(PutBitContext *pb, int dx, int dy)
{
int nbits, mask;
put_bits(pb, 1, 1); /* edge */
put_bits(pb, 1, 1); /* line select */
nbits = 2;
max_nbits(&nbits, dx);
max_nbits(&nbits, dy);
mask = (1 << nbits) - 1;
put_bits(pb, 4, nbits - 2); /* 16 bits precision */
if (dx == 0) {
put_bits(pb, 1, 0);
put_bits(pb, 1, 1);
put_bits(pb, nbits, dy & mask);
} else if (dy == 0) {
put_bits(pb, 1, 0);
put_bits(pb, 1, 0);
put_bits(pb, nbits, dx & mask);
} else {
put_bits(pb, 1, 1);
put_bits(pb, nbits, dx & mask);
put_bits(pb, nbits, dy & mask);
}
}
#define FRAC_BITS 16
static void put_swf_matrix(AVIOContext *pb,
int a, int b, int c, int d, int tx, int ty)
{
PutBitContext p;
uint8_t buf[256];
int nbits;
init_put_bits(&p, buf, sizeof(buf));
put_bits(&p, 1, 1); /* a, d present */
nbits = 1;
max_nbits(&nbits, a);
max_nbits(&nbits, d);
put_bits(&p, 5, nbits); /* nb bits */
put_bits(&p, nbits, a);
put_bits(&p, nbits, d);
put_bits(&p, 1, 1); /* b, c present */
nbits = 1;
max_nbits(&nbits, c);
max_nbits(&nbits, b);
put_bits(&p, 5, nbits); /* nb bits */
put_bits(&p, nbits, c);
put_bits(&p, nbits, b);
nbits = 1;
max_nbits(&nbits, tx);
max_nbits(&nbits, ty);
put_bits(&p, 5, nbits); /* nb bits */
put_bits(&p, nbits, tx);
put_bits(&p, nbits, ty);
flush_put_bits(&p);
avio_write(pb, buf, put_bits_ptr(&p) - p.buf);
}
static int swf_write_header(AVFormatContext *s)
{
SWFEncContext *swf = s->priv_data;
AVIOContext *pb = s->pb;
PutBitContext p;
uint8_t buf1[256];
int i, width, height, rate, rate_base;
int version;
swf->sound_samples = 0;
swf->swf_frame_number = 0;
swf->video_frame_number = 0;
for(i=0;i<s->nb_streams;i++) {
AVCodecParameters *par = s->streams[i]->codecpar;
if (par->codec_type == AVMEDIA_TYPE_AUDIO) {
if (swf->audio_par) {
av_log(s, AV_LOG_ERROR, "SWF muxer only supports 1 audio stream\n");
return AVERROR_INVALIDDATA;
}
if (par->codec_id == AV_CODEC_ID_MP3) {
swf->audio_par = par;
swf->audio_fifo = av_fifo_alloc2(AUDIO_FIFO_SIZE, 1, 0);
if (!swf->audio_fifo)
return AVERROR(ENOMEM);
} else {
av_log(s, AV_LOG_ERROR, "SWF muxer only supports MP3\n");
return -1;
}
} else {
if (swf->video_par) {
av_log(s, AV_LOG_ERROR, "SWF muxer only supports 1 video stream\n");
return AVERROR_INVALIDDATA;
}
if (ff_codec_get_tag(ff_swf_codec_tags, par->codec_id) ||
par->codec_id == AV_CODEC_ID_PNG ||
par->codec_id == AV_CODEC_ID_MJPEG) {
swf->video_st = s->streams[i];
swf->video_par = par;
} else {
av_log(s, AV_LOG_ERROR, "SWF muxer only supports VP6, FLV, Flash Screen Video, PNG and MJPEG\n");
return -1;
}
}
}
if (!swf->video_par) {
/* currently, cannot work correctly if audio only */
width = 320;
height = 200;
rate = 10;
rate_base= 1;
} else {
width = swf->video_par->width;
height = swf->video_par->height;
// TODO: should be avg_frame_rate
rate = swf->video_st->time_base.den;
rate_base = swf->video_st->time_base.num;
}
if (!swf->audio_par)
swf->samples_per_frame = (44100LL * rate_base) / rate;
else
swf->samples_per_frame = (swf->audio_par->sample_rate * rate_base) / rate;
avio_write(pb, "FWS", 3);
if (!strcmp("avm2", s->oformat->name))
version = 9;
else if (swf->video_par && (swf->video_par->codec_id == AV_CODEC_ID_VP6A ||
swf->video_par->codec_id == AV_CODEC_ID_VP6F ||
swf->video_par->codec_id == AV_CODEC_ID_PNG))
version = 8; /* version 8 and above support VP6 and PNG codec */
else if (swf->video_par && swf->video_par->codec_id == AV_CODEC_ID_FLASHSV)
version = 7; /* version 7 and above support Flash Screen Video codec */
else if (swf->video_par && swf->video_par->codec_id == AV_CODEC_ID_FLV1)
version = 6; /* version 6 and above support FLV1 codec */
else
version = 4; /* version 4 for mpeg audio support */
avio_w8(pb, version);
avio_wl32(pb, DUMMY_FILE_SIZE); /* dummy size
(will be patched if not streamed) */
put_swf_rect(pb, 0, width * 20, 0, height * 20);
if ((rate * 256LL) / rate_base >= (1<<16)) {
av_log(s, AV_LOG_ERROR, "Invalid (too large) frame rate %d/%d\n", rate, rate_base);
return AVERROR(EINVAL);
}
avio_wl16(pb, (rate * 256LL) / rate_base); /* frame rate */
swf->duration_pos = avio_tell(pb);
avio_wl16(pb, (uint16_t)(DUMMY_DURATION * (int64_t)rate / rate_base)); /* frame count */
/* swf v8 and later files require a file attribute tag */
if (version >= 8) {
put_swf_tag(s, TAG_FILEATTRIBUTES);
avio_wl32(pb, (version >= 9) << 3); /* set ActionScript v3/AVM2 flag */
put_swf_end_tag(s);
}
/* define a shape with the jpeg inside */
if (swf->video_par && (swf->video_par->codec_id == AV_CODEC_ID_MJPEG || swf->video_par->codec_id == AV_CODEC_ID_PNG)) {
put_swf_tag(s, TAG_DEFINESHAPE);
avio_wl16(pb, SHAPE_ID); /* ID of shape */
/* bounding rectangle */
put_swf_rect(pb, 0, width, 0, height);
/* style info */
avio_w8(pb, 1); /* one fill style */
avio_w8(pb, 0x41); /* clipped bitmap fill */
avio_wl16(pb, BITMAP_ID); /* bitmap ID */
/* position of the bitmap */
put_swf_matrix(pb, 1 << FRAC_BITS, 0,
0, 1 << FRAC_BITS, 0, 0);
avio_w8(pb, 0); /* no line style */
/* shape drawing */
init_put_bits(&p, buf1, sizeof(buf1));
put_bits(&p, 4, 1); /* one fill bit */
put_bits(&p, 4, 0); /* zero line bit */
put_bits(&p, 1, 0); /* not an edge */
put_bits(&p, 5, FLAG_MOVETO | FLAG_SETFILL0);
put_bits(&p, 5, 1); /* nbits */
put_bits(&p, 1, 0); /* X */
put_bits(&p, 1, 0); /* Y */
put_bits(&p, 1, 1); /* set fill style 1 */
/* draw the rectangle ! */
put_swf_line_edge(&p, width, 0);
put_swf_line_edge(&p, 0, height);
put_swf_line_edge(&p, -width, 0);
put_swf_line_edge(&p, 0, -height);
/* end of shape */
put_bits(&p, 1, 0); /* not an edge */
put_bits(&p, 5, 0);
flush_put_bits(&p);
avio_write(pb, buf1, put_bits_ptr(&p) - p.buf);
put_swf_end_tag(s);
}
if (swf->audio_par && swf->audio_par->codec_id == AV_CODEC_ID_MP3) {
int v = 0;
/* start sound */
put_swf_tag(s, TAG_STREAMHEAD2);
switch(swf->audio_par->sample_rate) {
case 11025: v |= 1 << 2; break;
case 22050: v |= 2 << 2; break;
case 44100: v |= 3 << 2; break;
default:
/* not supported */
av_log(s, AV_LOG_ERROR, "swf does not support that sample rate, choose from (44100, 22050, 11025).\n");
return -1;
}
v |= 0x02; /* 16 bit playback */
if (swf->audio_par->channels == 2)
v |= 0x01; /* stereo playback */
avio_w8(s->pb, v);
v |= 0x20; /* mp3 compressed */
avio_w8(s->pb, v);
avio_wl16(s->pb, swf->samples_per_frame); /* avg samples per frame */
avio_wl16(s->pb, 0);
put_swf_end_tag(s);
}
return 0;
}
static int fifo_avio_wrapper(void *opaque, void *buf, size_t *nb_elems)
{
avio_write(opaque, buf, *nb_elems);
return 0;
}
static int swf_write_video(AVFormatContext *s,
AVCodecParameters *par, const uint8_t *buf, int size, unsigned pkt_flags)
{
SWFEncContext *swf = s->priv_data;
AVIOContext *pb = s->pb;
unsigned codec_tag = ff_codec_get_tag(ff_swf_codec_tags, par->codec_id);
/* Flash Player limit */
if (swf->swf_frame_number == 16000)
av_log(s, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
if (codec_tag) {
if (swf->video_frame_number == 0) {
/* create a new video object */
put_swf_tag(s, TAG_VIDEOSTREAM);
avio_wl16(pb, VIDEO_ID);
swf->vframes_pos = avio_tell(pb);
avio_wl16(pb, 15000); /* hard flash player limit */
avio_wl16(pb, par->width);
avio_wl16(pb, par->height);
avio_w8(pb, 0);
avio_w8(pb, codec_tag);
put_swf_end_tag(s);
/* place the video object for the first time */
put_swf_tag(s, TAG_PLACEOBJECT2);
avio_w8(pb, 0x36);
avio_wl16(pb, 1);
avio_wl16(pb, VIDEO_ID);
put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
avio_wl16(pb, swf->video_frame_number);
avio_write(pb, "video", 5);
avio_w8(pb, 0x00);
put_swf_end_tag(s);
} else {
/* mark the character for update */
put_swf_tag(s, TAG_PLACEOBJECT2);
avio_w8(pb, 0x11);
avio_wl16(pb, 1);
avio_wl16(pb, swf->video_frame_number);
put_swf_end_tag(s);
}
/* set video frame data */
put_swf_tag(s, TAG_VIDEOFRAME | TAG_LONG);
avio_wl16(pb, VIDEO_ID);
avio_wl16(pb, swf->video_frame_number++);
if (par->codec_id == AV_CODEC_ID_FLASHSV) {
/* FrameType and CodecId is needed here even if it is not documented correctly in the SWF specs */
int flags = codec_tag | (pkt_flags & AV_PKT_FLAG_KEY ? FLV_FRAME_KEY : FLV_FRAME_INTER);
avio_w8(pb, flags);
}
avio_write(pb, buf, size);
put_swf_end_tag(s);
} else if (par->codec_id == AV_CODEC_ID_MJPEG || par->codec_id == AV_CODEC_ID_PNG) {
if (swf->swf_frame_number > 0) {
/* remove the shape */
put_swf_tag(s, TAG_REMOVEOBJECT);
avio_wl16(pb, SHAPE_ID); /* shape ID */
avio_wl16(pb, 1); /* depth */
put_swf_end_tag(s);
/* free the bitmap */
put_swf_tag(s, TAG_FREECHARACTER);
avio_wl16(pb, BITMAP_ID);
put_swf_end_tag(s);
}
put_swf_tag(s, TAG_JPEG2 | TAG_LONG);
avio_wl16(pb, BITMAP_ID); /* ID of the image */
/* a dummy jpeg header seems to be required */
if (par->codec_id == AV_CODEC_ID_MJPEG)
avio_wb32(pb, 0xffd8ffd9);
/* write the jpeg/png image */
avio_write(pb, buf, size);
put_swf_end_tag(s);
/* draw the shape */
put_swf_tag(s, TAG_PLACEOBJECT);
avio_wl16(pb, SHAPE_ID); /* shape ID */
avio_wl16(pb, 1); /* depth */
put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);
put_swf_end_tag(s);
}
swf->swf_frame_number++;
/* streaming sound always should be placed just before showframe tags */
if (swf->audio_par && av_fifo_can_read(swf->audio_fifo)) {
size_t frame_size = av_fifo_can_read(swf->audio_fifo);
put_swf_tag(s, TAG_STREAMBLOCK | TAG_LONG);
avio_wl16(pb, swf->sound_samples);
avio_wl16(pb, 0); // seek samples
av_fifo_read_to_cb(swf->audio_fifo, fifo_avio_wrapper, pb, &frame_size);
put_swf_end_tag(s);
/* update FIFO */
swf->sound_samples = 0;
}
/* output the frame */
put_swf_tag(s, TAG_SHOWFRAME);
put_swf_end_tag(s);
return 0;
}
static int swf_write_audio(AVFormatContext *s,
AVCodecParameters *par, uint8_t *buf, int size)
{
SWFEncContext *swf = s->priv_data;
/* Flash Player limit */
if (swf->swf_frame_number == 16000)
av_log(s, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
if (av_fifo_can_write(swf->audio_fifo) < size) {
av_log(s, AV_LOG_ERROR, "audio fifo too small to mux audio essence\n");
return -1;
}
av_fifo_write(swf->audio_fifo, buf, size);
swf->sound_samples += av_get_audio_frame_duration2(par, size);
/* if audio only stream make sure we add swf frames */
if (!swf->video_par)
swf_write_video(s, par, 0, 0, 0);
return 0;
}
static int swf_write_packet(AVFormatContext *s, AVPacket *pkt)
{
AVCodecParameters *par = s->streams[pkt->stream_index]->codecpar;
if (par->codec_type == AVMEDIA_TYPE_AUDIO)
return swf_write_audio(s, par, pkt->data, pkt->size);
else
return swf_write_video(s, par, pkt->data, pkt->size, pkt->flags);
}
static int swf_write_trailer(AVFormatContext *s)
{
SWFEncContext *swf = s->priv_data;
AVIOContext *pb = s->pb;
int file_size;
put_swf_tag(s, TAG_END);
put_swf_end_tag(s);
/* patch file size and number of frames if not streamed */
if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) && swf->video_par) {
file_size = avio_tell(pb);
avio_seek(pb, 4, SEEK_SET);
avio_wl32(pb, file_size);
avio_seek(pb, swf->duration_pos, SEEK_SET);
avio_wl16(pb, swf->video_frame_number);
if (swf->vframes_pos) {
avio_seek(pb, swf->vframes_pos, SEEK_SET);
avio_wl16(pb, swf->video_frame_number);
}
avio_seek(pb, file_size, SEEK_SET);
}
return 0;
}
static void swf_deinit(AVFormatContext *s)
{
SWFEncContext *swf = s->priv_data;
av_fifo_freep2(&swf->audio_fifo);
}
#if CONFIG_SWF_MUXER
const AVOutputFormat ff_swf_muxer = {
.name = "swf",
.long_name = NULL_IF_CONFIG_SMALL("SWF (ShockWave Flash)"),
.mime_type = "application/x-shockwave-flash",
.extensions = "swf",
.priv_data_size = sizeof(SWFEncContext),
.audio_codec = AV_CODEC_ID_MP3,
.video_codec = AV_CODEC_ID_FLV1,
.write_header = swf_write_header,
.write_packet = swf_write_packet,
.write_trailer = swf_write_trailer,
.deinit = swf_deinit,
.flags = AVFMT_TS_NONSTRICT,
};
#endif
#if CONFIG_AVM2_MUXER
const AVOutputFormat ff_avm2_muxer = {
.name = "avm2",
.long_name = NULL_IF_CONFIG_SMALL("SWF (ShockWave Flash) (AVM2)"),
.mime_type = "application/x-shockwave-flash",
.priv_data_size = sizeof(SWFEncContext),
.audio_codec = AV_CODEC_ID_MP3,
.video_codec = AV_CODEC_ID_FLV1,
.write_header = swf_write_header,
.write_packet = swf_write_packet,
.write_trailer = swf_write_trailer,
.deinit = swf_deinit,
.flags = AVFMT_TS_NONSTRICT,
};
#endif