[FFmpeg-devel] [PATCH 2/4] avcodec/encode: restructure the core encoding code
James Almer
jamrial at gmail.com
Thu Feb 27 20:02:00 EET 2020
This commit follows the same logic as 061a0c14bb, but for the encode API: The
new public encoding API will no longer be a wrapper around the old deprecated
one, and the internal API used by the encoders now consists of a single
receive_packet() callback that pulls frames as required.
Signed-off-by: James Almer <jamrial at gmail.com>
---
libavcodec/avcodec.h | 12 +-
libavcodec/encode.c | 268 ++++++++++++++++++++++++++++++++----------
libavcodec/encode.h | 39 ++++++
libavcodec/internal.h | 7 +-
libavcodec/utils.c | 12 +-
5 files changed, 268 insertions(+), 70 deletions(-)
create mode 100644 libavcodec/encode.h
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 894a9e5565..9d22390dd3 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -3641,14 +3641,10 @@ typedef struct AVCodec {
int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
int (*close)(AVCodecContext *);
/**
- * Encode API with decoupled packet/frame dataflow. The API is the
- * same as the avcodec_ prefixed APIs (avcodec_send_frame() etc.), except
- * that:
- * - never called if the codec is closed or the wrong type,
- * - if AV_CODEC_CAP_DELAY is not set, drain frames are never sent,
- * - only one drain frame is ever passed down,
- */
- int (*send_frame)(AVCodecContext *avctx, const AVFrame *frame);
+ * Encode API with decoupled frame/packet dataflow. This function is called
+ * to get one output packet. It should call ff_encode_get_packet() to obtain
+ * input data.
+ */
int (*receive_packet)(AVCodecContext *avctx, AVPacket *avpkt);
/**
diff --git a/libavcodec/encode.c b/libavcodec/encode.c
index 9ed2cf0f59..a887a0ab55 100644
--- a/libavcodec/encode.c
+++ b/libavcodec/encode.c
@@ -26,6 +26,7 @@
#include "libavutil/samplefmt.h"
#include "avcodec.h"
+#include "encode.h"
#include "frame_thread_encoder.h"
#include "internal.h"
@@ -359,101 +360,250 @@ int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
return ret;
}
-static int do_encode(AVCodecContext *avctx, const AVFrame *frame, int *got_packet)
+int ff_encode_get_frame(AVCodecContext *avctx, AVFrame *frame)
{
+ AVCodecInternal *avci = avctx->internal;
+
+ if (avci->draining)
+ return AVERROR_EOF;
+
+ if (!avci->buffer_frame->buf[0])
+ return AVERROR(EAGAIN);
+
+ av_frame_move_ref(frame, avci->buffer_frame);
+
+ return 0;
+}
+
+static int encode_simple_internal(AVCodecContext *avctx, AVPacket *avpkt)
+{
+ AVCodecInternal *avci = avctx->internal;
+ EncodeSimpleContext *es = &avci->es;
+ AVFrame *frame = es->in_frame;
+ AVFrame *padded_frame = NULL;
+ int got_packet;
int ret;
- *got_packet = 0;
- av_packet_unref(avctx->internal->buffer_pkt);
- avctx->internal->buffer_pkt_valid = 0;
+ if (!frame->buf[0] && !avci->draining) {
+ av_frame_unref(frame);
+ ret = ff_encode_get_frame(avctx, frame);
+ if (ret < 0 && ret != AVERROR_EOF)
+ return ret;
+ }
- if (avctx->codec_type == AVMEDIA_TYPE_VIDEO) {
- ret = avcodec_encode_video2(avctx, avctx->internal->buffer_pkt,
- frame, got_packet);
- } else if (avctx->codec_type == AVMEDIA_TYPE_AUDIO) {
- ret = avcodec_encode_audio2(avctx, avctx->internal->buffer_pkt,
- frame, got_packet);
- } else {
- ret = AVERROR(EINVAL);
+ if (avci->draining_done)
+ return AVERROR_EOF;
+
+ if (!frame->buf[0]) {
+ if (!(avctx->codec->capabilities & AV_CODEC_CAP_DELAY ||
+ avctx->active_thread_type & FF_THREAD_FRAME))
+ return AVERROR_EOF;
+
+ // Flushing is signaled with a NULL frame
+ frame = NULL;
+ }
+
+ got_packet = 0;
+
+ if (avctx->codec->type == AVMEDIA_TYPE_VIDEO) {
+ if ((avctx->flags & AV_CODEC_FLAG_PASS1) && avctx->stats_out)
+ avctx->stats_out[0] = '\0';
+
+ if (av_image_check_size2(avctx->width, avctx->height, avctx->max_pixels, AV_PIX_FMT_NONE, 0, avctx)) {
+ ret = AVERROR(EINVAL);
+ goto end;
+ }
+ if (frame) {
+ if (frame->format == AV_PIX_FMT_NONE)
+ av_log(avctx, AV_LOG_WARNING, "AVFrame.format is not set\n");
+ if (frame->width == 0 || frame->height == 0)
+ av_log(avctx, AV_LOG_WARNING, "AVFrame.width or height is not set\n");
+ }
+ } else if (frame && avctx->codec->type == AVMEDIA_TYPE_AUDIO) {
+ /* extract audio service type metadata */
+ AVFrameSideData *sd = av_frame_get_side_data(frame, AV_FRAME_DATA_AUDIO_SERVICE_TYPE);
+ if (sd && sd->size >= sizeof(enum AVAudioServiceType))
+ avctx->audio_service_type = *(enum AVAudioServiceType*)sd->data;
+
+ /* check for valid frame size */
+ if (avctx->codec->capabilities & AV_CODEC_CAP_SMALL_LAST_FRAME) {
+ if (frame->nb_samples > avctx->frame_size) {
+ av_log(avctx, AV_LOG_ERROR, "more samples than frame size (avcodec_encode_audio2)\n");
+ ret = AVERROR(EINVAL);
+ goto end;
+ }
+ } else if (!(avctx->codec->capabilities & AV_CODEC_CAP_VARIABLE_FRAME_SIZE)) {
+ /* if we already got an undersized frame, that must have been the last */
+ if (avctx->internal->last_audio_frame) {
+ av_log(avctx, AV_LOG_ERROR, "frame_size (%d) was not respected for a non-last frame (avcodec_encode_audio2)\n", avctx->frame_size);
+ ret = AVERROR(EINVAL);
+ goto end;
+ }
+
+ if (frame->nb_samples < avctx->frame_size) {
+ ret = pad_last_frame(avctx, &padded_frame, frame);
+ if (ret < 0)
+ goto end;
+
+ av_frame_unref(frame);
+ frame = padded_frame;
+ avctx->internal->last_audio_frame = 1;
+ }
+
+ if (frame->nb_samples != avctx->frame_size) {
+ av_log(avctx, AV_LOG_ERROR, "nb_samples (%d) != frame_size (%d) (avcodec_encode_audio2)\n", frame->nb_samples, avctx->frame_size);
+ ret = AVERROR(EINVAL);
+ goto end;
+ }
+ }
+ }
+
+ av_assert0(avctx->codec->encode2);
+
+ if (CONFIG_FRAME_THREAD_ENCODER &&
+ avci->frame_thread_encoder && (avctx->active_thread_type&FF_THREAD_FRAME))
+ ret = ff_thread_video_encode_frame(avctx, avpkt, frame, &got_packet);
+ else
+ ret = avctx->codec->encode2(avctx, avpkt, frame, &got_packet);
+
+ av_assert0(ret <= 0);
+
+ emms_c();
+
+ if (!ret && got_packet) {
+ if (avpkt->data) {
+ ret = av_packet_make_refcounted(avpkt);
+ if (ret < 0)
+ goto end;
+ }
+
+ if (frame && !(avctx->codec->capabilities & AV_CODEC_CAP_DELAY ||
+ avctx->active_thread_type & FF_THREAD_FRAME)) {
+ if (avctx->codec->type == AVMEDIA_TYPE_VIDEO) {
+ avpkt->pts = avpkt->dts = frame->pts;
+ } else if (avctx->codec->type == AVMEDIA_TYPE_AUDIO) {
+ if (avpkt->pts == AV_NOPTS_VALUE)
+ avpkt->pts = frame->pts;
+ if (!avpkt->duration)
+ avpkt->duration = ff_samples_to_time_base(avctx,
+ frame->nb_samples);
+ }
+ }
+ if (avctx->codec->type == AVMEDIA_TYPE_AUDIO) {
+ /* NOTE: if we add any audio encoders which output non-keyframe packets,
+ * this needs to be moved to the encoders, but for now we can do it
+ * here to simplify things */
+ avpkt->flags |= AV_PKT_FLAG_KEY;
+ avpkt->dts = avpkt->pts;
+ }
+ }
+
+ if (avci->draining && !got_packet)
+ avci->draining_done = 1;
+
+end:
+ if (ret < 0 || !got_packet)
+ av_packet_unref(avpkt);
+
+ if (frame) {
+ if (!ret)
+ avctx->frame_number++;
+ av_frame_unref(frame);
}
- if (ret >= 0 && *got_packet) {
+ av_frame_free(&padded_frame);
+
+ if (got_packet)
// Encoders must always return ref-counted buffers.
// Side-data only packets have no data and can be not ref-counted.
- av_assert0(!avctx->internal->buffer_pkt->data || avctx->internal->buffer_pkt->buf);
- avctx->internal->buffer_pkt_valid = 1;
- ret = 0;
- } else {
- av_packet_unref(avctx->internal->buffer_pkt);
+ av_assert0(!avpkt->data || avpkt->buf);
+
+ return ret;
+}
+
+static int encode_simple_receive_packet(AVCodecContext *avctx, AVPacket *avpkt)
+{
+ int ret;
+
+ while (!avpkt->data && !avpkt->side_data) {
+ ret = encode_simple_internal(avctx, avpkt);
+ if (ret < 0)
+ return ret;
}
+ return 0;
+}
+
+static int encode_receive_packet_internal(AVCodecContext *avctx, AVPacket *avpkt)
+{
+ AVCodecInternal *avci = avctx->internal;
+ int ret;
+
+ av_assert0(!avpkt->data && !avpkt->side_data);
+
+ if (avctx->codec->receive_packet) {
+ ret = avctx->codec->receive_packet(avctx, avpkt);
+ if (!ret)
+ // Encoders must always return ref-counted buffers.
+ // Side-data only packets have no data and can be not ref-counted.
+ av_assert0(!avpkt->data || avpkt->buf);
+ } else
+ ret = encode_simple_receive_packet(avctx, avpkt);
+
+ if (ret == AVERROR_EOF)
+ avci->draining_done = 1;
+
return ret;
}
int attribute_align_arg avcodec_send_frame(AVCodecContext *avctx, const AVFrame *frame)
{
+ AVCodecInternal *avci = avctx->internal;
+ int ret;
+
if (!avcodec_is_open(avctx) || !av_codec_is_encoder(avctx->codec))
return AVERROR(EINVAL);
- if (avctx->internal->draining)
+ if (avci->draining)
return AVERROR_EOF;
- if (!frame) {
- avctx->internal->draining = 1;
+ if (avci->buffer_frame->data[0])
+ return AVERROR(EAGAIN);
- if (!(avctx->codec->capabilities & AV_CODEC_CAP_DELAY))
- return 0;
+ if (!frame) {
+ avci->draining = 1;
+ } else {
+ ret = av_frame_ref(avci->buffer_frame, frame);
+ if (ret < 0)
+ return ret;
}
- if (avctx->codec->send_frame)
- return avctx->codec->send_frame(avctx, frame);
-
- // Emulation via old API. Do it here instead of avcodec_receive_packet, because:
- // 1. if the AVFrame is not refcounted, the copying will be much more
- // expensive than copying the packet data
- // 2. assume few users use non-refcounted AVPackets, so usually no copy is
- // needed
-
- if (avctx->internal->buffer_pkt_valid)
- return AVERROR(EAGAIN);
+ if (!avci->buffer_pkt->data && !avci->buffer_pkt->side_data) {
+ ret = encode_receive_packet_internal(avctx, avci->buffer_pkt);
+ if (ret < 0 && ret != AVERROR(EAGAIN) && ret != AVERROR_EOF)
+ return ret;
+ }
- return do_encode(avctx, frame, &(int){0});
+ return 0;
}
int attribute_align_arg avcodec_receive_packet(AVCodecContext *avctx, AVPacket *avpkt)
{
+ AVCodecInternal *avci = avctx->internal;
+ int ret;
+
av_packet_unref(avpkt);
if (!avcodec_is_open(avctx) || !av_codec_is_encoder(avctx->codec))
return AVERROR(EINVAL);
- if (avctx->codec->receive_packet) {
- int ret;
- if (avctx->internal->draining && !(avctx->codec->capabilities & AV_CODEC_CAP_DELAY))
- return AVERROR_EOF;
- ret = avctx->codec->receive_packet(avctx, avpkt);
- if (!ret)
- // Encoders must always return ref-counted buffers.
- // Side-data only packets have no data and can be not ref-counted.
- av_assert0(!avpkt->data || avpkt->buf);
- return ret;
- }
-
- // Emulation via old API.
-
- if (!avctx->internal->buffer_pkt_valid) {
- int got_packet;
- int ret;
- if (!avctx->internal->draining)
- return AVERROR(EAGAIN);
- ret = do_encode(avctx, NULL, &got_packet);
+ if (avci->buffer_pkt->data || avci->buffer_pkt->side_data) {
+ av_packet_move_ref(avpkt, avci->buffer_pkt);
+ } else {
+ ret = encode_receive_packet_internal(avctx, avpkt);
if (ret < 0)
return ret;
- if (ret >= 0 && !got_packet)
- return AVERROR_EOF;
}
- av_packet_move_ref(avpkt, avctx->internal->buffer_pkt);
- avctx->internal->buffer_pkt_valid = 0;
return 0;
}
diff --git a/libavcodec/encode.h b/libavcodec/encode.h
new file mode 100644
index 0000000000..2eef31251a
--- /dev/null
+++ b/libavcodec/encode.h
@@ -0,0 +1,39 @@
+/*
+ * generic encoding-related code
+ *
+ * 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
+ */
+
+#ifndef AVCODEC_ENCODE_H
+#define AVCODEC_ENCODE_H
+
+#include "libavutil/frame.h"
+
+#include "avcodec.h"
+
+/**
+ * Called by encoders to get the next frame for encoding.
+ *
+ * @param frame An empty frame to be filled with data.
+ * @return 0 if a new reference has been successfully written to frame
+ * AVERROR(EAGAIN) if no data is currently available
+ * AVERROR_EOF if and end of stream has been reached, so no more data
+ * will be available
+ */
+int ff_encode_get_frame(AVCodecContext *avctx, AVFrame *frame);
+
+#endif /* AVCODEC_ENCODE_H */
diff --git a/libavcodec/internal.h b/libavcodec/internal.h
index bccd9222d4..8b97e08e9f 100644
--- a/libavcodec/internal.h
+++ b/libavcodec/internal.h
@@ -132,6 +132,10 @@ typedef struct DecodeFilterContext {
int nb_bsfs;
} DecodeFilterContext;
+typedef struct EncodeSimpleContext {
+ AVFrame *in_frame;
+} EncodeSimpleContext;
+
typedef struct AVCodecInternal {
/**
* Whether the parent AVCodecContext is a copy of the context which had
@@ -171,6 +175,8 @@ typedef struct AVCodecInternal {
DecodeSimpleContext ds;
DecodeFilterContext filter;
+ EncodeSimpleContext es;
+
/**
* Properties (timestamps+side data) extracted from the last packet passed
* for decoding.
@@ -204,7 +210,6 @@ typedef struct AVCodecInternal {
* buffers for using new encode/decode API through legacy API
*/
AVPacket *buffer_pkt;
- int buffer_pkt_valid; // encoding: packet without data can be valid
AVFrame *buffer_frame;
int draining_done;
/* set to 1 when the caller is using the old decoding API */
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 5257a1c627..ccc08c2dfb 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -93,7 +93,7 @@ void av_fast_padded_mallocz(void *ptr, unsigned int *size, size_t min_size)
int av_codec_is_encoder(const AVCodec *codec)
{
- return codec && (codec->encode_sub || codec->encode2 ||codec->send_frame);
+ return codec && (codec->encode_sub || codec->encode2 || codec->receive_packet);
}
int av_codec_is_decoder(const AVCodec *codec)
@@ -607,6 +607,12 @@ int attribute_align_arg avcodec_open2(AVCodecContext *avctx, const AVCodec *code
goto free_and_end;
}
+ avci->es.in_frame = av_frame_alloc();
+ if (!avctx->internal->es.in_frame) {
+ ret = AVERROR(ENOMEM);
+ goto free_and_end;
+ }
+
avci->buffer_pkt = av_packet_alloc();
if (!avci->buffer_pkt) {
ret = AVERROR(ENOMEM);
@@ -1074,6 +1080,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
av_packet_free(&avci->last_pkt_props);
av_packet_free(&avci->ds.in_pkt);
+ av_frame_free(&avci->es.in_frame);
ff_decode_bsfs_uninit(avctx);
av_freep(&avci->pool);
@@ -1094,9 +1101,9 @@ void avcodec_flush_buffers(AVCodecContext *avctx)
av_frame_unref(avci->buffer_frame);
av_frame_unref(avci->compat_decode_frame);
av_packet_unref(avci->buffer_pkt);
- avci->buffer_pkt_valid = 0;
av_packet_unref(avci->ds.in_pkt);
+ av_frame_unref(avci->es.in_frame);
if (HAVE_THREADS && avctx->active_thread_type & FF_THREAD_FRAME)
ff_thread_flush(avctx);
@@ -1162,6 +1169,7 @@ av_cold int avcodec_close(AVCodecContext *avctx)
av_packet_free(&avctx->internal->last_pkt_props);
av_packet_free(&avctx->internal->ds.in_pkt);
+ av_frame_free(&avctx->internal->es.in_frame);
for (i = 0; i < FF_ARRAY_ELEMS(pool->pools); i++)
av_buffer_pool_uninit(&pool->pools[i]);
--
2.25.1
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