/* * JPEG XL decoding support via libjxl * Copyright (c) 2021 Leo Izen * * 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 */ /** * @file * JPEG XL decoder using libjxl */ #include "libavutil/avassert.h" #include "libavutil/buffer.h" #include "libavutil/common.h" #include "libavutil/csp.h" #include "libavutil/error.h" #include "libavutil/mem.h" #include "libavutil/pixdesc.h" #include "libavutil/pixfmt.h" #include "libavutil/frame.h" #include "avcodec.h" #include "codec_internal.h" #include "decode.h" #include #include #include "libjxl.h" typedef struct LibJxlDecodeContext { void *runner; JxlDecoder *decoder; JxlBasicInfo basic_info; JxlPixelFormat jxl_pixfmt; #if JPEGXL_NUMERIC_VERSION >= JPEGXL_COMPUTE_NUMERIC_VERSION(0, 8, 0) JxlBitDepth jxl_bit_depth; #endif JxlDecoderStatus events; AVBufferRef *iccp; } LibJxlDecodeContext; static int libjxl_init_jxl_decoder(AVCodecContext *avctx) { LibJxlDecodeContext *ctx = avctx->priv_data; ctx->events = JXL_DEC_BASIC_INFO | JXL_DEC_FULL_IMAGE | JXL_DEC_COLOR_ENCODING; if (JxlDecoderSubscribeEvents(ctx->decoder, ctx->events) != JXL_DEC_SUCCESS) { av_log(avctx, AV_LOG_ERROR, "Error subscribing to JXL events\n"); return AVERROR_EXTERNAL; } if (JxlDecoderSetParallelRunner(ctx->decoder, JxlThreadParallelRunner, ctx->runner) != JXL_DEC_SUCCESS) { av_log(avctx, AV_LOG_ERROR, "Failed to set JxlThreadParallelRunner\n"); return AVERROR_EXTERNAL; } memset(&ctx->basic_info, 0, sizeof(JxlBasicInfo)); memset(&ctx->jxl_pixfmt, 0, sizeof(JxlPixelFormat)); return 0; } static av_cold int libjxl_decode_init(AVCodecContext *avctx) { LibJxlDecodeContext *ctx = avctx->priv_data; JxlMemoryManager manager; ff_libjxl_init_memory_manager(&manager); ctx->decoder = JxlDecoderCreate(&manager); if (!ctx->decoder) { av_log(avctx, AV_LOG_ERROR, "Failed to create JxlDecoder\n"); return AVERROR_EXTERNAL; } ctx->runner = JxlThreadParallelRunnerCreate(&manager, ff_libjxl_get_threadcount(avctx->thread_count)); if (!ctx->runner) { av_log(avctx, AV_LOG_ERROR, "Failed to create JxlThreadParallelRunner\n"); return AVERROR_EXTERNAL; } return libjxl_init_jxl_decoder(avctx); } static enum AVPixelFormat libjxl_get_pix_fmt(AVCodecContext *avctx, LibJxlDecodeContext *ctx) { const JxlBasicInfo *basic_info = &ctx->basic_info; JxlPixelFormat *format = &ctx->jxl_pixfmt; format->endianness = JXL_NATIVE_ENDIAN; format->num_channels = basic_info->num_color_channels + (basic_info->alpha_bits > 0); #if JPEGXL_NUMERIC_VERSION >= JPEGXL_COMPUTE_NUMERIC_VERSION(0, 8, 0) ctx->jxl_bit_depth.bits_per_sample = avctx->bits_per_raw_sample = basic_info->bits_per_sample; ctx->jxl_bit_depth.type = JXL_BIT_DEPTH_FROM_PIXEL_FORMAT; ctx->jxl_bit_depth.exponent_bits_per_sample = basic_info->exponent_bits_per_sample; #endif /* Gray */ if (basic_info->num_color_channels == 1) { if (basic_info->bits_per_sample <= 8) { format->data_type = JXL_TYPE_UINT8; return basic_info->alpha_bits ? AV_PIX_FMT_YA8 : AV_PIX_FMT_GRAY8; } if (basic_info->exponent_bits_per_sample || basic_info->bits_per_sample > 16) { if (basic_info->alpha_bits) return AV_PIX_FMT_NONE; format->data_type = JXL_TYPE_FLOAT; return AV_PIX_FMT_GRAYF32; } format->data_type = JXL_TYPE_UINT16; return basic_info->alpha_bits ? AV_PIX_FMT_YA16 : AV_PIX_FMT_GRAY16; } /* rgb only */ /* libjxl only supports packed RGB and gray output at the moment */ if (basic_info->num_color_channels == 3) { if (basic_info->bits_per_sample <= 8) { format->data_type = JXL_TYPE_UINT8; return basic_info->alpha_bits ? AV_PIX_FMT_RGBA : AV_PIX_FMT_RGB24; } if (basic_info->exponent_bits_per_sample) av_log(avctx, AV_LOG_WARNING, "Downsampling float to 16-bit integer via libjxl\n"); else if (basic_info->bits_per_sample > 16) av_log(avctx, AV_LOG_WARNING, "Downsampling larger integer to 16-bit via libjxl\n"); format->data_type = JXL_TYPE_UINT16; return basic_info->alpha_bits ? AV_PIX_FMT_RGBA64 : AV_PIX_FMT_RGB48; } return AV_PIX_FMT_NONE; } static enum AVColorPrimaries libjxl_get_primaries(void *avctx, const JxlColorEncoding *jxl_color) { AVColorPrimariesDesc desc; enum AVColorPrimaries prim; /* libjxl populates these double values even if it uses an enum space */ desc.prim.r.x = av_d2q(jxl_color->primaries_red_xy[0], 300000); desc.prim.r.y = av_d2q(jxl_color->primaries_red_xy[1], 300000); desc.prim.g.x = av_d2q(jxl_color->primaries_green_xy[0], 300000); desc.prim.g.y = av_d2q(jxl_color->primaries_green_xy[1], 300000); desc.prim.b.x = av_d2q(jxl_color->primaries_blue_xy[0], 300000); desc.prim.b.y = av_d2q(jxl_color->primaries_blue_xy[1], 300000); desc.wp.x = av_d2q(jxl_color->white_point_xy[0], 300000); desc.wp.y = av_d2q(jxl_color->white_point_xy[1], 300000); prim = av_csp_primaries_id_from_desc(&desc); if (prim == AVCOL_PRI_UNSPECIFIED) { /* try D65 with the same primaries */ /* BT.709 uses D65 white point */ desc.wp = av_csp_primaries_desc_from_id(AVCOL_PRI_BT709)->wp; av_log(avctx, AV_LOG_WARNING, "Changing unknown white point to D65\n"); prim = av_csp_primaries_id_from_desc(&desc); } return prim; } static enum AVColorTransferCharacteristic libjxl_get_trc(void *avctx, const JxlColorEncoding *jxl_color) { switch (jxl_color->transfer_function) { case JXL_TRANSFER_FUNCTION_709: return AVCOL_TRC_BT709; case JXL_TRANSFER_FUNCTION_LINEAR: return AVCOL_TRC_LINEAR; case JXL_TRANSFER_FUNCTION_SRGB: return AVCOL_TRC_IEC61966_2_1; case JXL_TRANSFER_FUNCTION_PQ: return AVCOL_TRC_SMPTE2084; case JXL_TRANSFER_FUNCTION_DCI: return AVCOL_TRC_SMPTE428; case JXL_TRANSFER_FUNCTION_HLG: return AVCOL_TRC_ARIB_STD_B67; case JXL_TRANSFER_FUNCTION_GAMMA: if (jxl_color->gamma > 0.45355 && jxl_color->gamma < 0.45555) return AVCOL_TRC_GAMMA22; else if (jxl_color->gamma > 0.35614 && jxl_color->gamma < 0.35814) return AVCOL_TRC_GAMMA28; else av_log(avctx, AV_LOG_WARNING, "Unsupported gamma transfer: %f\n", jxl_color->gamma); break; default: av_log(avctx, AV_LOG_WARNING, "Unknown transfer function: %d\n", jxl_color->transfer_function); } return AVCOL_TRC_UNSPECIFIED; } static int libjxl_get_icc(AVCodecContext *avctx) { LibJxlDecodeContext *ctx = avctx->priv_data; size_t icc_len; JxlDecoderStatus jret; /* an ICC profile is present, and we can meaningfully get it, * because the pixel data is not XYB-encoded */ jret = JxlDecoderGetICCProfileSize(ctx->decoder, &ctx->jxl_pixfmt, JXL_COLOR_PROFILE_TARGET_DATA, &icc_len); if (jret == JXL_DEC_SUCCESS && icc_len > 0) { av_buffer_unref(&ctx->iccp); ctx->iccp = av_buffer_alloc(icc_len); if (!ctx->iccp) return AVERROR(ENOMEM); jret = JxlDecoderGetColorAsICCProfile(ctx->decoder, &ctx->jxl_pixfmt, JXL_COLOR_PROFILE_TARGET_DATA, ctx->iccp->data, icc_len); if (jret != JXL_DEC_SUCCESS) { av_log(avctx, AV_LOG_WARNING, "Unable to obtain ICC Profile\n"); av_buffer_unref(&ctx->iccp); } } return 0; } /* * There's generally four cases when it comes to decoding a libjxl image * with regard to color encoding: * (a) There is an embedded ICC profile in the image, and the image is XYB-encoded. * (b) There is an embedded ICC profile in the image, and the image is not XYB-encoded. * (c) There is no embedded ICC profile, and FFmpeg supports the tagged colorspace. * (d) There is no embedded ICC profile, and FFmpeg does not support the tagged colorspace. * * In case (b), we forward the pixel data as is and forward the ICC Profile as-is. * In case (c), we request the pixel data in the space it's tagged as, * and tag the space accordingly. * In case (a), libjxl does not support getting the pixel data in the space described by the ICC * profile, so instead we request the pixel data in BT.2020/PQ as it is the widest * space that FFmpeg supports. * In case (d), we also request wide-gamut pixel data as a fallback since FFmpeg doesn't support * the custom primaries tagged in the space. */ static int libjxl_color_encoding_event(AVCodecContext *avctx, AVFrame *frame) { LibJxlDecodeContext *ctx = avctx->priv_data; JxlDecoderStatus jret; int ret; JxlColorEncoding jxl_color; /* set this flag if we need to fall back on wide gamut */ int fallback = 0; jret = JxlDecoderGetColorAsEncodedProfile(ctx->decoder, NULL, JXL_COLOR_PROFILE_TARGET_ORIGINAL, &jxl_color); if (jret == JXL_DEC_SUCCESS) { /* enum values describe the colors of this image */ jret = JxlDecoderSetPreferredColorProfile(ctx->decoder, &jxl_color); if (jret == JXL_DEC_SUCCESS) jret = JxlDecoderGetColorAsEncodedProfile(ctx->decoder, &ctx->jxl_pixfmt, JXL_COLOR_PROFILE_TARGET_DATA, &jxl_color); /* if we couldn't successfully request the pixel data space, we fall back on wide gamut */ /* this code path is very unlikely to happen in practice */ if (jret != JXL_DEC_SUCCESS) fallback = 1; } else { /* an ICC Profile is present in the stream */ if (ctx->basic_info.uses_original_profile) { /* uses_original_profile is the same as !xyb_encoded */ av_log(avctx, AV_LOG_VERBOSE, "Using embedded ICC Profile\n"); if ((ret = libjxl_get_icc(avctx)) < 0) return ret; } else { /* * an XYB-encoded image with an embedded ICC profile can't always have the * pixel data requested in the original space, so libjxl has no feature * to allow this to happen, so we fall back on wide gamut */ fallback = 1; } } avctx->color_range = frame->color_range = AVCOL_RANGE_JPEG; if (ctx->jxl_pixfmt.num_channels >= 3) avctx->colorspace = AVCOL_SPC_RGB; avctx->color_primaries = AVCOL_PRI_UNSPECIFIED; avctx->color_trc = AVCOL_TRC_UNSPECIFIED; if (!ctx->iccp) { /* checking enum values */ if (!fallback) { if (avctx->colorspace == AVCOL_SPC_RGB) avctx->color_primaries = libjxl_get_primaries(avctx, &jxl_color); avctx->color_trc = libjxl_get_trc(avctx, &jxl_color); } /* fall back on wide gamut if enum values fail */ if (avctx->color_primaries == AVCOL_PRI_UNSPECIFIED) { if (avctx->colorspace == AVCOL_SPC_RGB) { av_log(avctx, AV_LOG_WARNING, "Falling back on wide gamut output\n"); jxl_color.primaries = JXL_PRIMARIES_2100; avctx->color_primaries = AVCOL_PRI_BT2020; } /* libjxl requires this set even for grayscale */ jxl_color.white_point = JXL_WHITE_POINT_D65; } if (avctx->color_trc == AVCOL_TRC_UNSPECIFIED) { if (ctx->jxl_pixfmt.data_type == JXL_TYPE_FLOAT || ctx->jxl_pixfmt.data_type == JXL_TYPE_FLOAT16) { av_log(avctx, AV_LOG_WARNING, "Falling back on Linear Light transfer\n"); jxl_color.transfer_function = JXL_TRANSFER_FUNCTION_LINEAR; avctx->color_trc = AVCOL_TRC_LINEAR; } else { av_log(avctx, AV_LOG_WARNING, "Falling back on iec61966-2-1/sRGB transfer\n"); jxl_color.transfer_function = JXL_TRANSFER_FUNCTION_SRGB; avctx->color_trc = AVCOL_TRC_IEC61966_2_1; } } /* all colors will be in-gamut so we want accurate colors */ jxl_color.rendering_intent = JXL_RENDERING_INTENT_RELATIVE; jxl_color.color_space = avctx->colorspace == AVCOL_SPC_RGB ? JXL_COLOR_SPACE_RGB : JXL_COLOR_SPACE_GRAY; jret = JxlDecoderSetPreferredColorProfile(ctx->decoder, &jxl_color); if (jret != JXL_DEC_SUCCESS) { av_log(avctx, AV_LOG_WARNING, "Unable to set fallback color encoding\n"); /* * This should only happen if there's a non-XYB encoded image with custom primaries * embedded as enums and no embedded ICC Profile. * In this case, libjxl will synthesize an ICC Profile for us. */ avctx->color_trc = AVCOL_TRC_UNSPECIFIED; avctx->color_primaries = AVCOL_PRI_UNSPECIFIED; if ((ret = libjxl_get_icc(avctx)) < 0) return ret; } } frame->color_trc = avctx->color_trc; frame->color_primaries = avctx->color_primaries; frame->colorspace = avctx->colorspace; return 0; } static int libjxl_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *avpkt) { LibJxlDecodeContext *ctx = avctx->priv_data; const uint8_t *buf = avpkt->data; size_t remaining = avpkt->size; JxlDecoderStatus jret; int ret; *got_frame = 0; while (1) { jret = JxlDecoderSetInput(ctx->decoder, buf, remaining); if (jret == JXL_DEC_ERROR) { /* this should never happen here unless there's a bug in libjxl */ av_log(avctx, AV_LOG_ERROR, "Unknown libjxl decode error\n"); return AVERROR_EXTERNAL; } jret = JxlDecoderProcessInput(ctx->decoder); /* * JxlDecoderReleaseInput returns the number * of bytes remaining to be read, rather than * the number of bytes that it did read */ remaining = JxlDecoderReleaseInput(ctx->decoder); buf = avpkt->data + avpkt->size - remaining; switch(jret) { case JXL_DEC_ERROR: av_log(avctx, AV_LOG_ERROR, "Unknown libjxl decode error\n"); return AVERROR_INVALIDDATA; case JXL_DEC_NEED_MORE_INPUT: if (remaining == 0) { av_log(avctx, AV_LOG_ERROR, "Unexpected end of JXL codestream\n"); return AVERROR_INVALIDDATA; } av_log(avctx, AV_LOG_DEBUG, "NEED_MORE_INPUT event emitted\n"); continue; case JXL_DEC_BASIC_INFO: av_log(avctx, AV_LOG_DEBUG, "BASIC_INFO event emitted\n"); if (JxlDecoderGetBasicInfo(ctx->decoder, &ctx->basic_info) != JXL_DEC_SUCCESS) { /* * this should never happen * if it does it is likely a libjxl decoder bug */ av_log(avctx, AV_LOG_ERROR, "Bad libjxl basic info event\n"); return AVERROR_EXTERNAL; } avctx->pix_fmt = libjxl_get_pix_fmt(avctx, ctx); if (avctx->pix_fmt == AV_PIX_FMT_NONE) { av_log(avctx, AV_LOG_ERROR, "Bad libjxl pixel format\n"); return AVERROR_EXTERNAL; } if ((ret = ff_set_dimensions(avctx, ctx->basic_info.xsize, ctx->basic_info.ysize)) < 0) return ret; continue; case JXL_DEC_COLOR_ENCODING: av_log(avctx, AV_LOG_DEBUG, "COLOR_ENCODING event emitted\n"); if ((ret = libjxl_color_encoding_event(avctx, frame)) < 0) return ret; continue; case JXL_DEC_NEED_IMAGE_OUT_BUFFER: av_log(avctx, AV_LOG_DEBUG, "NEED_IMAGE_OUT_BUFFER event emitted\n"); if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) return ret; ctx->jxl_pixfmt.align = frame->linesize[0]; if (JxlDecoderSetImageOutBuffer(ctx->decoder, &ctx->jxl_pixfmt, frame->data[0], frame->buf[0]->size) != JXL_DEC_SUCCESS) { av_log(avctx, AV_LOG_ERROR, "Bad libjxl dec need image out buffer event\n"); return AVERROR_EXTERNAL; } #if JPEGXL_NUMERIC_VERSION >= JPEGXL_COMPUTE_NUMERIC_VERSION(0, 8, 0) if (JxlDecoderSetImageOutBitDepth(ctx->decoder, &ctx->jxl_bit_depth) != JXL_DEC_SUCCESS) { av_log(avctx, AV_LOG_ERROR, "Error setting output bit depth\n"); return AVERROR_EXTERNAL; } #endif continue; case JXL_DEC_FULL_IMAGE: /* full image is one frame, even if animated */ av_log(avctx, AV_LOG_DEBUG, "FULL_IMAGE event emitted\n"); frame->pict_type = AV_PICTURE_TYPE_I; frame->flags |= AV_FRAME_FLAG_KEY; if (ctx->iccp) { AVFrameSideData *sd = av_frame_new_side_data_from_buf(frame, AV_FRAME_DATA_ICC_PROFILE, ctx->iccp); if (!sd) return AVERROR(ENOMEM); /* ownership is transfered, and it is not ref-ed */ ctx->iccp = NULL; } *got_frame = 1; return avpkt->size - remaining; case JXL_DEC_SUCCESS: av_log(avctx, AV_LOG_DEBUG, "SUCCESS event emitted\n"); /* * The SUCCESS event isn't fired until after JXL_DEC_FULL_IMAGE. If this * stream only contains one JXL image then JXL_DEC_SUCCESS will never fire. * If the image2 sequence being decoded contains several JXL files, then * libjxl will fire this event after the next AVPacket has been passed, * which means the current packet is actually the next image in the sequence. * This is why we reset the decoder and populate the packet data now, since * this is the next packet and it has not been decoded yet. The decoder does * have to be reset to allow us to use it for the next image, or libjxl * will become very confused if the header information is not identical. */ JxlDecoderReset(ctx->decoder); libjxl_init_jxl_decoder(avctx); buf = avpkt->data; remaining = avpkt->size; continue; default: av_log(avctx, AV_LOG_ERROR, "Bad libjxl event: %d\n", jret); return AVERROR_EXTERNAL; } } } static av_cold int libjxl_decode_close(AVCodecContext *avctx) { LibJxlDecodeContext *ctx = avctx->priv_data; if (ctx->runner) JxlThreadParallelRunnerDestroy(ctx->runner); ctx->runner = NULL; if (ctx->decoder) JxlDecoderDestroy(ctx->decoder); ctx->decoder = NULL; av_buffer_unref(&ctx->iccp); return 0; } const FFCodec ff_libjxl_decoder = { .p.name = "libjxl", CODEC_LONG_NAME("libjxl JPEG XL"), .p.type = AVMEDIA_TYPE_VIDEO, .p.id = AV_CODEC_ID_JPEGXL, .priv_data_size = sizeof(LibJxlDecodeContext), .init = libjxl_decode_init, FF_CODEC_DECODE_CB(libjxl_decode_frame), .close = libjxl_decode_close, .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_OTHER_THREADS, .caps_internal = FF_CODEC_CAP_NOT_INIT_THREADSAFE | FF_CODEC_CAP_AUTO_THREADS | FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_ICC_PROFILES, .p.wrapper_name = "libjxl", };