FFmpeg/libavcodec/imm5.c
Andreas Rheinhardt 4e1fee405f avcodec: Fix invalid uses of ff_codec_open2_recursive()
Normally no two codecs with FF_CODEC_CAP_INIT_THREADSAFE unset
can be initialized at the same time: a mutex in avcodec_open2()
ensures this. This implies that one cannot simply open a codec
with a non-threadsafe init-function from the init function of
a codec whose own init function is not threadsafe either as the child
codec couldn't acquire the lock.

ff_codec_open2_recursive() exists to get around this limitation:
If the init function of the child codec to be initialized is not
thread-safe, the mutex is unlocked, the child is initialized and
the mutex is locked again. This of course has as a prerequisite that
the parent AVCodecContext actually holds the lock, i.e. that the
parent codec's init function is not thread-safe. If it is, then one
can (and has to) just use avcodec_open2() directly (if the child's
init function is not thread-safe, then avcodec_open2() will have to
acquire the mutex itself (and potentially wait for it), so that it is
perfectly fine for an otherwise thread-safe init function to open
a codec with a potentially non-thread-safe init function via
avcodec_open2()).

Yet several of the users of ff_codec_open2_recursive() have the
FF_CODEC_CAP_INIT_THREADSAFE flag set; this only worked because
all the child codecs' init functions were thread-safe themselves
so that ff_codec_open2_recursive() didn't touch the mutex at all.
But of course the real solution to this is to directly use
avcodec_open2().

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
2020-12-04 15:46:46 +01:00

194 lines
6.6 KiB
C

/*
* Copyright (c) 2019 Paul B Mahol
*
* 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 "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "internal.h"
typedef struct IMM5Context {
AVCodecContext *h264_avctx; // wrapper context for H264
AVCodecContext *hevc_avctx; // wrapper context for HEVC
} IMM5Context;
static const struct IMM5_unit {
uint8_t bits[14];
uint8_t len;
} IMM5_units[14] = {
{ { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0x80, 0x1E, 0xF4, 0x0B, 0x0F, 0x88 }, 12 },
{ { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0x80, 0x1E, 0xF4, 0x05, 0x83, 0xE2 }, 12 },
{ { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0x80, 0x1E, 0xF4, 0x05, 0x81, 0xE8, 0x80 }, 13 },
{ { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0x80, 0x1E, 0xF4, 0x0B, 0x04, 0xA2 }, 12 },
{ { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0x80, 0x1E, 0xF4, 0x05, 0x81, 0x28, 0x80 }, 13 },
{ { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0x80, 0x1E, 0xF4, 0x05, 0x80, 0x92, 0x20 }, 13 },
{ { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0x00, 0x1E, 0x9A, 0x74, 0x0B, 0x0F, 0xC8 }, 13 },
{ { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0x00, 0x1E, 0x9A, 0x74, 0x05, 0x83, 0xF2 }, 13 },
{ { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0x00, 0x1E, 0x9A, 0x74, 0x05, 0x81, 0xEC, 0x80 }, 14 },
{ { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0x00, 0x1E, 0x9A, 0x74, 0x0B, 0x04, 0xB2 }, 13 },
{ { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0x00, 0x1E, 0x9A, 0x74, 0x05, 0x81, 0x2C, 0x80 }, 14 },
{ { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0x00, 0x1E, 0x9A, 0x74, 0x05, 0x80, 0x93, 0x20 }, 14 },
{ { 0x00, 0x00, 0x00, 0x01, 0x68, 0xDE, 0x3C, 0x80 }, 8 },
{ { 0x00, 0x00, 0x00, 0x01, 0x68, 0xCE, 0x32, 0x28 }, 8 },
};
static av_cold int imm5_init(AVCodecContext *avctx)
{
IMM5Context *ctx = avctx->priv_data;
const AVCodec *codec;
int ret;
codec = avcodec_find_decoder(AV_CODEC_ID_H264);
if (!codec)
return AVERROR_BUG;
ctx->h264_avctx = avcodec_alloc_context3(codec);
if (!ctx->h264_avctx)
return AVERROR(ENOMEM);
ctx->h264_avctx->thread_count = 1;
ctx->h264_avctx->flags = avctx->flags;
ctx->h264_avctx->flags2 = avctx->flags2;
ret = avcodec_open2(ctx->h264_avctx, codec, NULL);
if (ret < 0)
return ret;
codec = avcodec_find_decoder(AV_CODEC_ID_HEVC);
if (!codec)
return AVERROR_BUG;
ctx->hevc_avctx = avcodec_alloc_context3(codec);
if (!ctx->hevc_avctx)
return AVERROR(ENOMEM);
ctx->hevc_avctx->thread_count = 1;
ctx->hevc_avctx->flags = avctx->flags;
ctx->hevc_avctx->flags2 = avctx->flags2;
ret = avcodec_open2(ctx->hevc_avctx, codec, NULL);
if (ret < 0)
return ret;
return 0;
}
static int imm5_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame, AVPacket *avpkt)
{
IMM5Context *ctx = avctx->priv_data;
AVFrame *frame = data;
AVCodecContext *codec_avctx = ctx->h264_avctx;
int ret;
if (avpkt->size > 24 && avpkt->data[8] <= 1 && AV_RL32(avpkt->data + 4) + 24ULL <= avpkt->size) {
int codec_type = avpkt->data[1];
int index = avpkt->data[10];
int new_size = AV_RL32(avpkt->data + 4);
int offset, off;
if (codec_type == 0xA) {
codec_avctx = ctx->hevc_avctx;
} else if (index == 17) {
index = 4;
} else if (index == 18) {
index = 5;
}
if (index >= 1 && index <= 12) {
ret = av_packet_make_writable(avpkt);
if (ret < 0)
return ret;
index -= 1;
off = offset = IMM5_units[index].len;
if (codec_type == 2) {
offset += IMM5_units[12].len;
} else {
offset += IMM5_units[13].len;
}
avpkt->data += 24 - offset;
avpkt->size = new_size + offset;
memcpy(avpkt->data, IMM5_units[index].bits, IMM5_units[index].len);
if (codec_type == 2) {
memcpy(avpkt->data + off, IMM5_units[12].bits, IMM5_units[12].len);
} else {
memcpy(avpkt->data + off, IMM5_units[13].bits, IMM5_units[13].len);
}
} else {
avpkt->data += 24;
avpkt->size -= 24;
}
}
ret = avcodec_send_packet(codec_avctx, avpkt);
if (ret < 0) {
av_log(avctx, AV_LOG_ERROR, "Error submitting a packet for decoding\n");
return ret;
}
ret = avcodec_receive_frame(codec_avctx, frame);
if (ret < 0)
return ret;
avctx->pix_fmt = codec_avctx->pix_fmt;
avctx->coded_width = codec_avctx->coded_width;
avctx->coded_height = codec_avctx->coded_height;
avctx->width = codec_avctx->width;
avctx->height = codec_avctx->height;
avctx->bit_rate = codec_avctx->bit_rate;
avctx->colorspace = codec_avctx->colorspace;
avctx->color_range = codec_avctx->color_range;
avctx->color_trc = codec_avctx->color_trc;
avctx->color_primaries = codec_avctx->color_primaries;
avctx->chroma_sample_location = codec_avctx->chroma_sample_location;
*got_frame = 1;
return avpkt->size;
}
static void imm5_flush(AVCodecContext *avctx)
{
IMM5Context *ctx = avctx->priv_data;
avcodec_flush_buffers(ctx->h264_avctx);
avcodec_flush_buffers(ctx->hevc_avctx);
}
static av_cold int imm5_close(AVCodecContext *avctx)
{
IMM5Context *ctx = avctx->priv_data;
avcodec_free_context(&ctx->h264_avctx);
avcodec_free_context(&ctx->hevc_avctx);
return 0;
}
AVCodec ff_imm5_decoder = {
.name = "imm5",
.long_name = NULL_IF_CONFIG_SMALL("Infinity IMM5"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_IMM5,
.init = imm5_init,
.decode = imm5_decode_frame,
.close = imm5_close,
.flush = imm5_flush,
.priv_data_size = sizeof(IMM5Context),
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
FF_CODEC_CAP_INIT_CLEANUP,
};