blob: 8ab90fad9c6825788dcee56e3df6b6dca5450fb9 [file] [log] [blame]
/*
* Copyright 2019 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "experimental/ffmpeg/SkVideoEncoder.h"
#include "include/core/SkColorSpace.h"
#include "include/core/SkImage.h"
#include "include/private/SkTDArray.h"
extern "C" {
#include "libswscale/swscale.h"
}
class SkRandomAccessWStream {
SkTDArray<char> fStorage;
size_t fPos = 0;
public:
SkRandomAccessWStream() {}
size_t pos() const { return fPos; }
size_t size() const { return fStorage.size(); }
void write(const void* src, size_t bytes) {
size_t len = fStorage.size();
SkASSERT(fPos <= len);
size_t overwrite = std::min(len - fPos, bytes);
if (overwrite) {
SkDebugf("overwrite %zu bytes at %zu offset with %zu remaining\n", overwrite, fPos, bytes - overwrite);
memcpy(&fStorage[fPos], src, overwrite);
fPos += overwrite;
src = (const char*)src + overwrite;
bytes -= overwrite;
}
// bytes now represents the amount to append
if (bytes) {
fStorage.append(bytes, (const char*)src);
fPos += bytes;
}
SkASSERT(fPos <= fStorage.size());
}
void seek(size_t pos) {
SkASSERT(pos <= fStorage.size());
fPos = pos;
}
sk_sp<SkData> detachAsData() {
// TODO: could add an efficient detach to SkTDArray if we wanted, w/o copy
return SkData::MakeWithCopy(fStorage.begin(), fStorage.size());
}
};
///////////////////////////////////////////////////////////////////////////////////////////////////
// returns true on error (and may dump the particular error message)
static bool check_err(int err, const int silentList[] = nullptr) {
if (err >= 0) {
return false;
}
if (silentList) {
for (; *silentList; ++silentList) {
if (*silentList == err) {
return true; // we still report the error, but we don't printf
}
}
}
char errbuf[128];
const char *errbuf_ptr = errbuf;
if (av_strerror(err, errbuf, sizeof(errbuf)) < 0) {
errbuf_ptr = strerror(AVUNERROR(err));
}
SkDebugf("%s\n", errbuf_ptr);
return true;
}
static int sk_write_packet(void* ctx, uint8_t* buffer, int size) {
SkRandomAccessWStream* stream = (SkRandomAccessWStream*)ctx;
stream->write(buffer, size);
return size;
}
static int64_t sk_seek_packet(void* ctx, int64_t pos, int whence) {
SkRandomAccessWStream* stream = (SkRandomAccessWStream*)ctx;
switch (whence) {
case SEEK_SET:
break;
case SEEK_CUR:
pos = (int64_t)stream->pos() + pos;
break;
case SEEK_END:
pos = (int64_t)stream->size() + pos;
break;
default:
return -1;
}
if (pos < 0 || pos > (int64_t)stream->size()) {
return -1;
}
stream->seek(SkToSizeT(pos));
return pos;
}
SkVideoEncoder::SkVideoEncoder() {
fInfo = SkImageInfo::MakeUnknown();
}
SkVideoEncoder::~SkVideoEncoder() {
this->reset();
if (fSWScaleCtx) {
sws_freeContext(fSWScaleCtx);
}
}
void SkVideoEncoder::reset() {
if (fFrame) {
av_frame_free(&fFrame);
fFrame = nullptr;
}
if (fEncoderCtx) {
avcodec_free_context(&fEncoderCtx);
fEncoderCtx = nullptr;
}
if (fFormatCtx) {
avformat_free_context(fFormatCtx);
fFormatCtx = nullptr;
}
av_packet_free(&fPacket);
fPacket = nullptr;
fSurface.reset();
fWStream.reset();
}
bool SkVideoEncoder::init(int fps) {
// only support this for now
AVPixelFormat pix_fmt = AV_PIX_FMT_YUV420P;
this->reset();
fWStream.reset(new SkRandomAccessWStream);
int bufferSize = 4 * 1024;
uint8_t* buffer = (uint8_t*)av_malloc(bufferSize);
if (!buffer) {
return false;
}
fStreamCtx = avio_alloc_context(buffer, bufferSize, AVIO_FLAG_WRITE, fWStream.get(),
nullptr, sk_write_packet, sk_seek_packet);
SkASSERT(fStreamCtx);
avformat_alloc_output_context2(&fFormatCtx, nullptr, "mp4", nullptr);
SkASSERT(fFormatCtx);
fFormatCtx->pb = fStreamCtx;
AVOutputFormat *output_format = fFormatCtx->oformat;
if (output_format->video_codec == AV_CODEC_ID_NONE) {
return false;
}
AVCodec* codec = avcodec_find_encoder(output_format->video_codec);
SkASSERT(codec);
fStream = avformat_new_stream(fFormatCtx, codec);
SkASSERT(fStream);
fStream->id = fFormatCtx->nb_streams-1;
fStream->time_base = (AVRational){ 1, fps };
fEncoderCtx = avcodec_alloc_context3(codec);
SkASSERT(fEncoderCtx);
fEncoderCtx->codec_id = output_format->video_codec;
fEncoderCtx->width = fInfo.width();
fEncoderCtx->height = fInfo.height();
fEncoderCtx->time_base = fStream->time_base;
fEncoderCtx->pix_fmt = pix_fmt;
/* Some formats want stream headers to be separate. */
if (output_format->flags & AVFMT_GLOBALHEADER) {
fEncoderCtx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
}
if (check_err(avcodec_open2(fEncoderCtx, codec, nullptr))) {
return false;
}
fFrame = av_frame_alloc();
SkASSERT(fFrame);
fFrame->format = pix_fmt;
fFrame->width = fEncoderCtx->width;
fFrame->height = fEncoderCtx->height;
if (check_err(av_frame_get_buffer(fFrame, 32))) {
return false;
}
if (check_err(avcodec_parameters_from_context(fStream->codecpar, fEncoderCtx))) {
return false;
}
if (check_err(avformat_write_header(fFormatCtx, nullptr))) {
return false;
}
fPacket = av_packet_alloc();
return true;
}
#include "include/core/SkCanvas.h"
#include "include/core/SkColorFilter.h"
#include "include/core/SkSurface.h"
#include "src/core/SkYUVMath.h"
static bool is_valid(SkISize dim) {
if (dim.width() <= 0 || dim.height() <= 0) {
return false;
}
// need the dimensions to be even for YUV 420
return ((dim.width() | dim.height()) & 1) == 0;
}
bool SkVideoEncoder::beginRecording(SkISize dim, int fps) {
if (!is_valid(dim)) {
return false;
}
SkAlphaType alphaType = kOpaque_SkAlphaType;
sk_sp<SkColorSpace> cs = nullptr; // should we use this?
fInfo = SkImageInfo::MakeN32(dim.width(), dim.height(), alphaType, cs);
if (!this->init(fps)) {
return false;
}
fCurrentPTS = 0;
fDeltaPTS = 1;
const auto fmt = kN32_SkColorType == kRGBA_8888_SkColorType ? AV_PIX_FMT_RGBA : AV_PIX_FMT_BGRA;
SkASSERT(sws_isSupportedInput(fmt) > 0);
SkASSERT(sws_isSupportedOutput(AV_PIX_FMT_YUV420P) > 0);
// sws_getCachedContext takes in either null or a previous ctx. It returns either a new ctx,
// or the same as the input if it is compatible with the inputs. Thus we never have to
// explicitly release our ctx until the destructor, since sws_getCachedContext takes care
// of freeing the old as needed if/when it returns a new one.
fSWScaleCtx = sws_getCachedContext(fSWScaleCtx,
dim.width(), dim.height(), fmt,
dim.width(), dim.height(), AV_PIX_FMT_YUV420P,
SWS_FAST_BILINEAR, nullptr, nullptr, nullptr);
return fSWScaleCtx != nullptr;
}
bool SkVideoEncoder::addFrame(const SkPixmap& pm) {
if (!is_valid(pm.dimensions())) {
return false;
}
if (pm.info().colorType() != fInfo.colorType()) {
return false;
}
/* make sure the frame data is writable */
if (check_err(av_frame_make_writable(fFrame))) {
return false;
}
fFrame->pts = fCurrentPTS;
fCurrentPTS += fDeltaPTS;
const uint8_t* src[] = { (const uint8_t*)pm.addr() };
const int strides[] = { SkToInt(pm.rowBytes()) };
sws_scale(fSWScaleCtx, src, strides, 0, fInfo.height(), fFrame->data, fFrame->linesize);
return this->sendFrame(fFrame);
}
bool SkVideoEncoder::sendFrame(AVFrame* frame) {
if (check_err(avcodec_send_frame(fEncoderCtx, frame))) {
return false;
}
int ret = 0;
while (ret >= 0) {
ret = avcodec_receive_packet(fEncoderCtx, fPacket);
if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
break;
}
if (check_err(ret)) {
return false;
}
av_packet_rescale_ts(fPacket, fEncoderCtx->time_base, fStream->time_base);
SkASSERT(fPacket->stream_index == fStream->index);
if (check_err(av_interleaved_write_frame(fFormatCtx, fPacket))) {
return false;
}
}
return true;
}
SkCanvas* SkVideoEncoder::beginFrame() {
if (!fSurface) {
fSurface = SkSurface::MakeRaster(fInfo);
if (!fSurface) {
return nullptr;
}
}
SkCanvas* canvas = fSurface->getCanvas();
canvas->restoreToCount(1);
canvas->clear(0);
return canvas;
}
bool SkVideoEncoder::endFrame() {
if (!fSurface) {
return false;
}
SkPixmap pm;
return fSurface->peekPixels(&pm) && this->addFrame(pm);
}
sk_sp<SkData> SkVideoEncoder::endRecording() {
if (!fFormatCtx) {
return nullptr;
}
this->sendFrame(nullptr);
av_write_trailer(fFormatCtx);
sk_sp<SkData> data = fWStream->detachAsData();
this->reset();
return data;
}