1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-02 03:06:28 +02:00
FFmpeg/libavcodec/mpegpicture.c
Andreas Rheinhardt e506843183 avcodec/mpegpicture: Reset fields explicitly instead of memsetting them
Improves the grepability of the code.
(Furthermore, I hope that no compiler will really call memset
for 28 bytes.)

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-08-18 16:57:47 +02:00

467 lines
15 KiB
C

/*
* Mpeg video formats-related picture management functions
*
* 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 <stdint.h>
#include "libavutil/avassert.h"
#include "libavutil/common.h"
#include "libavutil/pixdesc.h"
#include "libavutil/imgutils.h"
#include "avcodec.h"
#include "encode.h"
#include "motion_est.h"
#include "mpegpicture.h"
#include "mpegutils.h"
#include "threadframe.h"
static void av_noinline free_picture_tables(Picture *pic)
{
pic->alloc_mb_width =
pic->alloc_mb_height = 0;
av_buffer_unref(&pic->mbskip_table_buf);
av_buffer_unref(&pic->qscale_table_buf);
av_buffer_unref(&pic->mb_type_buf);
for (int i = 0; i < 2; i++) {
av_buffer_unref(&pic->motion_val_buf[i]);
av_buffer_unref(&pic->ref_index_buf[i]);
}
}
static int make_table_writable(AVBufferRef **ref)
{
AVBufferRef *old = *ref, *new;
if (av_buffer_is_writable(old))
return 0;
new = av_buffer_allocz(old->size);
if (!new)
return AVERROR(ENOMEM);
av_buffer_unref(ref);
*ref = new;
return 0;
}
static int make_tables_writable(Picture *pic)
{
#define MAKE_WRITABLE(table) \
do {\
int ret = make_table_writable(&pic->table); \
if (ret < 0) \
return ret; \
} while (0)
MAKE_WRITABLE(mbskip_table_buf);
MAKE_WRITABLE(qscale_table_buf);
MAKE_WRITABLE(mb_type_buf);
if (pic->motion_val_buf[0]) {
for (int i = 0; i < 2; i++) {
MAKE_WRITABLE(motion_val_buf[i]);
MAKE_WRITABLE(ref_index_buf[i]);
}
}
return 0;
}
int ff_mpeg_framesize_alloc(AVCodecContext *avctx, MotionEstContext *me,
ScratchpadContext *sc, int linesize)
{
# define EMU_EDGE_HEIGHT (4 * 70)
int alloc_size = FFALIGN(FFABS(linesize) + 64, 32);
if (avctx->hwaccel)
return 0;
if (linesize < 24) {
av_log(avctx, AV_LOG_ERROR, "Image too small, temporary buffers cannot function\n");
return AVERROR_PATCHWELCOME;
}
if (av_image_check_size2(alloc_size, EMU_EDGE_HEIGHT, avctx->max_pixels, AV_PIX_FMT_NONE, 0, avctx) < 0)
return AVERROR(ENOMEM);
// edge emu needs blocksize + filter length - 1
// (= 17x17 for halfpel / 21x21 for H.264)
// VC-1 computes luma and chroma simultaneously and needs 19X19 + 9x9
// at uvlinesize. It supports only YUV420 so 24x24 is enough
// linesize * interlaced * MBsize
// we also use this buffer for encoding in encode_mb_internal() needig an additional 32 lines
if (!FF_ALLOCZ_TYPED_ARRAY(sc->edge_emu_buffer, alloc_size * EMU_EDGE_HEIGHT) ||
!FF_ALLOCZ_TYPED_ARRAY(me->scratchpad, alloc_size * 4 * 16 * 2)) {
av_freep(&sc->edge_emu_buffer);
return AVERROR(ENOMEM);
}
me->temp = me->scratchpad;
sc->rd_scratchpad = me->scratchpad;
sc->b_scratchpad = me->scratchpad;
sc->obmc_scratchpad = me->scratchpad + 16;
return 0;
}
/**
* Allocate a frame buffer
*/
static int alloc_frame_buffer(AVCodecContext *avctx, Picture *pic,
MotionEstContext *me, ScratchpadContext *sc,
int chroma_x_shift, int chroma_y_shift,
int linesize, int uvlinesize)
{
int edges_needed = av_codec_is_encoder(avctx->codec);
int r, ret;
pic->tf.f = pic->f;
if (edges_needed) {
pic->f->width = avctx->width + 2 * EDGE_WIDTH;
pic->f->height = avctx->height + 2 * EDGE_WIDTH;
r = ff_encode_alloc_frame(avctx, pic->f);
} else if (avctx->codec_id != AV_CODEC_ID_WMV3IMAGE &&
avctx->codec_id != AV_CODEC_ID_VC1IMAGE &&
avctx->codec_id != AV_CODEC_ID_MSS2) {
r = ff_thread_get_ext_buffer(avctx, &pic->tf,
pic->reference ? AV_GET_BUFFER_FLAG_REF : 0);
} else {
pic->f->width = avctx->width;
pic->f->height = avctx->height;
pic->f->format = avctx->pix_fmt;
r = avcodec_default_get_buffer2(avctx, pic->f, 0);
}
if (r < 0 || !pic->f->buf[0]) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed (%d %p)\n",
r, pic->f->data[0]);
return -1;
}
if (edges_needed) {
int i;
for (i = 0; pic->f->data[i]; i++) {
int offset = (EDGE_WIDTH >> (i ? chroma_y_shift : 0)) *
pic->f->linesize[i] +
(EDGE_WIDTH >> (i ? chroma_x_shift : 0));
pic->f->data[i] += offset;
}
pic->f->width = avctx->width;
pic->f->height = avctx->height;
}
if (avctx->hwaccel) {
assert(!pic->hwaccel_picture_private);
if (avctx->hwaccel->frame_priv_data_size) {
pic->hwaccel_priv_buf = av_buffer_allocz(avctx->hwaccel->frame_priv_data_size);
if (!pic->hwaccel_priv_buf) {
av_log(avctx, AV_LOG_ERROR, "alloc_frame_buffer() failed (hwaccel private data allocation)\n");
return -1;
}
pic->hwaccel_picture_private = pic->hwaccel_priv_buf->data;
}
}
if ((linesize && linesize != pic->f->linesize[0]) ||
(uvlinesize && uvlinesize != pic->f->linesize[1])) {
av_log(avctx, AV_LOG_ERROR,
"get_buffer() failed (stride changed: linesize=%d/%d uvlinesize=%d/%d)\n",
linesize, pic->f->linesize[0],
uvlinesize, pic->f->linesize[1]);
ff_mpeg_unref_picture(avctx, pic);
return -1;
}
if (av_pix_fmt_count_planes(pic->f->format) > 2 &&
pic->f->linesize[1] != pic->f->linesize[2]) {
av_log(avctx, AV_LOG_ERROR,
"get_buffer() failed (uv stride mismatch)\n");
ff_mpeg_unref_picture(avctx, pic);
return -1;
}
if (!sc->edge_emu_buffer &&
(ret = ff_mpeg_framesize_alloc(avctx, me, sc,
pic->f->linesize[0])) < 0) {
av_log(avctx, AV_LOG_ERROR,
"get_buffer() failed to allocate context scratch buffers.\n");
ff_mpeg_unref_picture(avctx, pic);
return ret;
}
return 0;
}
static int alloc_picture_tables(AVCodecContext *avctx, Picture *pic, int encoding, int out_format,
int mb_stride, int mb_width, int mb_height, int b8_stride)
{
const int big_mb_num = mb_stride * (mb_height + 1) + 1;
const int mb_array_size = mb_stride * mb_height;
const int b8_array_size = b8_stride * mb_height * 2;
int i;
pic->mbskip_table_buf = av_buffer_allocz(mb_array_size + 2);
pic->qscale_table_buf = av_buffer_allocz(big_mb_num + mb_stride);
pic->mb_type_buf = av_buffer_allocz((big_mb_num + mb_stride) *
sizeof(uint32_t));
if (!pic->mbskip_table_buf || !pic->qscale_table_buf || !pic->mb_type_buf)
return AVERROR(ENOMEM);
if (out_format == FMT_H263 || encoding ||
(avctx->export_side_data & AV_CODEC_EXPORT_DATA_MVS)) {
int mv_size = 2 * (b8_array_size + 4) * sizeof(int16_t);
int ref_index_size = 4 * mb_array_size;
for (i = 0; mv_size && i < 2; i++) {
pic->motion_val_buf[i] = av_buffer_allocz(mv_size);
pic->ref_index_buf[i] = av_buffer_allocz(ref_index_size);
if (!pic->motion_val_buf[i] || !pic->ref_index_buf[i])
return AVERROR(ENOMEM);
}
}
pic->alloc_mb_width = mb_width;
pic->alloc_mb_height = mb_height;
pic->alloc_mb_stride = mb_stride;
return 0;
}
/**
* Allocate a Picture.
* The pixels are allocated/set by calling get_buffer() if shared = 0
*/
int ff_alloc_picture(AVCodecContext *avctx, Picture *pic, MotionEstContext *me,
ScratchpadContext *sc, int shared, int encoding,
int chroma_x_shift, int chroma_y_shift, int out_format,
int mb_stride, int mb_width, int mb_height, int b8_stride,
ptrdiff_t *linesize, ptrdiff_t *uvlinesize)
{
int i, ret;
if (pic->qscale_table_buf)
if ( pic->alloc_mb_width != mb_width
|| pic->alloc_mb_height != mb_height)
free_picture_tables(pic);
if (shared) {
av_assert0(pic->f->data[0]);
pic->shared = 1;
} else {
av_assert0(!pic->f->buf[0]);
if (alloc_frame_buffer(avctx, pic, me, sc,
chroma_x_shift, chroma_y_shift,
*linesize, *uvlinesize) < 0)
return -1;
*linesize = pic->f->linesize[0];
*uvlinesize = pic->f->linesize[1];
}
if (!pic->qscale_table_buf)
ret = alloc_picture_tables(avctx, pic, encoding, out_format,
mb_stride, mb_width, mb_height, b8_stride);
else
ret = make_tables_writable(pic);
if (ret < 0)
goto fail;
pic->mbskip_table = pic->mbskip_table_buf->data;
pic->qscale_table = pic->qscale_table_buf->data + 2 * mb_stride + 1;
pic->mb_type = (uint32_t*)pic->mb_type_buf->data + 2 * mb_stride + 1;
if (pic->motion_val_buf[0]) {
for (i = 0; i < 2; i++) {
pic->motion_val[i] = (int16_t (*)[2])pic->motion_val_buf[i]->data + 4;
pic->ref_index[i] = pic->ref_index_buf[i]->data;
}
}
return 0;
fail:
av_log(avctx, AV_LOG_ERROR, "Error allocating a picture.\n");
ff_mpeg_unref_picture(avctx, pic);
free_picture_tables(pic);
return AVERROR(ENOMEM);
}
/**
* Deallocate a picture; frees the picture tables in case they
* need to be reallocated anyway.
*/
void ff_mpeg_unref_picture(AVCodecContext *avctx, Picture *pic)
{
pic->tf.f = pic->f;
/* WM Image / Screen codecs allocate internal buffers with different
* dimensions / colorspaces; ignore user-defined callbacks for these. */
if (avctx->codec_id != AV_CODEC_ID_WMV3IMAGE &&
avctx->codec_id != AV_CODEC_ID_VC1IMAGE &&
avctx->codec_id != AV_CODEC_ID_MSS2)
ff_thread_release_ext_buffer(avctx, &pic->tf);
else if (pic->f)
av_frame_unref(pic->f);
av_buffer_unref(&pic->hwaccel_priv_buf);
if (pic->needs_realloc)
free_picture_tables(pic);
pic->hwaccel_picture_private = NULL;
pic->field_picture = 0;
pic->b_frame_score = 0;
pic->needs_realloc = 0;
pic->reference = 0;
pic->shared = 0;
}
int ff_update_picture_tables(Picture *dst, const Picture *src)
{
int i, ret;
ret = av_buffer_replace(&dst->mbskip_table_buf, src->mbskip_table_buf);
ret |= av_buffer_replace(&dst->qscale_table_buf, src->qscale_table_buf);
ret |= av_buffer_replace(&dst->mb_type_buf, src->mb_type_buf);
for (i = 0; i < 2; i++) {
ret |= av_buffer_replace(&dst->motion_val_buf[i], src->motion_val_buf[i]);
ret |= av_buffer_replace(&dst->ref_index_buf[i], src->ref_index_buf[i]);
}
if (ret < 0) {
free_picture_tables(dst);
return ret;
}
dst->mbskip_table = src->mbskip_table;
dst->qscale_table = src->qscale_table;
dst->mb_type = src->mb_type;
for (i = 0; i < 2; i++) {
dst->motion_val[i] = src->motion_val[i];
dst->ref_index[i] = src->ref_index[i];
}
dst->alloc_mb_width = src->alloc_mb_width;
dst->alloc_mb_height = src->alloc_mb_height;
dst->alloc_mb_stride = src->alloc_mb_stride;
return 0;
}
int ff_mpeg_ref_picture(AVCodecContext *avctx, Picture *dst, Picture *src)
{
int ret;
av_assert0(!dst->f->buf[0]);
av_assert0(src->f->buf[0]);
src->tf.f = src->f;
dst->tf.f = dst->f;
ret = ff_thread_ref_frame(&dst->tf, &src->tf);
if (ret < 0)
goto fail;
ret = ff_update_picture_tables(dst, src);
if (ret < 0)
goto fail;
if (src->hwaccel_picture_private) {
dst->hwaccel_priv_buf = av_buffer_ref(src->hwaccel_priv_buf);
if (!dst->hwaccel_priv_buf) {
ret = AVERROR(ENOMEM);
goto fail;
}
dst->hwaccel_picture_private = dst->hwaccel_priv_buf->data;
}
dst->field_picture = src->field_picture;
dst->b_frame_score = src->b_frame_score;
dst->needs_realloc = src->needs_realloc;
dst->reference = src->reference;
dst->shared = src->shared;
return 0;
fail:
ff_mpeg_unref_picture(avctx, dst);
return ret;
}
static inline int pic_is_unused(Picture *pic)
{
if (!pic->f->buf[0])
return 1;
if (pic->needs_realloc)
return 1;
return 0;
}
static int find_unused_picture(AVCodecContext *avctx, Picture *picture, int shared)
{
int i;
if (shared) {
for (i = 0; i < MAX_PICTURE_COUNT; i++) {
if (!picture[i].f->buf[0])
return i;
}
} else {
for (i = 0; i < MAX_PICTURE_COUNT; i++) {
if (pic_is_unused(&picture[i]))
return i;
}
}
av_log(avctx, AV_LOG_FATAL,
"Internal error, picture buffer overflow\n");
/* We could return -1, but the codec would crash trying to draw into a
* non-existing frame anyway. This is safer than waiting for a random crash.
* Also the return of this is never useful, an encoder must only allocate
* as much as allowed in the specification. This has no relationship to how
* much libavcodec could allocate (and MAX_PICTURE_COUNT is always large
* enough for such valid streams).
* Plus, a decoder has to check stream validity and remove frames if too
* many reference frames are around. Waiting for "OOM" is not correct at
* all. Similarly, missing reference frames have to be replaced by
* interpolated/MC frames, anything else is a bug in the codec ...
*/
abort();
return -1;
}
int ff_find_unused_picture(AVCodecContext *avctx, Picture *picture, int shared)
{
int ret = find_unused_picture(avctx, picture, shared);
if (ret >= 0 && ret < MAX_PICTURE_COUNT) {
if (picture[ret].needs_realloc) {
ff_mpeg_unref_picture(avctx, &picture[ret]);
}
}
return ret;
}
void av_cold ff_mpv_picture_free(AVCodecContext *avctx, Picture *pic)
{
free_picture_tables(pic);
ff_mpeg_unref_picture(avctx, pic);
av_frame_free(&pic->f);
}